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Proto:Sonic the Hedgehog 2 (Genesis)/Nick Arcade Prototype/Zones

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This is a sub-page of Proto:Sonic the Hedgehog 2 (Genesis)/Nick Arcade Prototype.


At this point in development, the game uses the Zone names and music from Sonic 1. The Sonic 1 title cards are present and intact, but are invisible because the commands to display them are preceded by a return command. Removing the return commands will show the title cards with the Sonic 2 palette.

To do:
Specify where the return commands are in hex.

Green Hill Zone

Believe it or not, I'm walking on air...

As you'd expect, it's Green Hill from Sonic 1...except now with broken collision and glitched/missing graphics.

  • Because of the different collision array, most slopes make Sonic fall out of the level and die.
  • The S-bend tubes are broken as well, with the engine treating most of them as invisible barriers.
  • The original collision array data from Sonic 1 is present in the ROM, and can be restored with a set of Game Genie codes: AA1A-CEAL AA1A-CEFT AA2A-CEB0 AA2A-CEB6 AA0T-CAG6 AA1A-CAEC AA1T-CAA2 AA1T-CAF8 AA2A-CADJ AA2A-CADR AA1T-DECG AA1T-DEHN AA2A-DECN. Using these, it plays perfectly beside the broken art and the weird collision with collapsing grounds. There is a dummied out function that gets called that is meant to override the Sonic 2 collision array data with Sonic 1's if in this zone, which would've functioned on the development carts used. However, on a regular cartridge, the code doesn't work at all.
  • All of the necessary data for Green Hill is still present, and has even been updated to use Sonic 2's data formats. For example, the level's tilemaps have been changed from 256×256 to 128×128, and the art has been updated to look correct in 2-Player mode. Unfortunately, this is also one of the main reasons the object art is broken.
  • Act 3's boss' camera lock is 160 pixels to the left of its usual spot.
  • All three Acts have different monitors than Sonic 1, showing that the pointers for the monitor types were changed early in development.
    • Related to this, all Sonic 1-Up monitors are Tails 1-Up monitors.
  • Crabmeat has unused art from Sonic 1 in his sprite.
  • The Sonic 1-style springs are present here, whereas the other Zones in this build use the Sonic 2 style.
  • The only badnik whose graphics remain intact is the Piranha. However, due to Sonic's palette having been updated, the coloration is glitchy.
  • The spikes are the updated Sonic 2 variants and use the correct graphics when seen in Debug Mode, but have glitchy graphics when placed or encountered in normal gameplay.
  • Green Hill's palette was not updated to Sonic 2's palette standard, so the spike graphics when viewed in Debug Mode use one color (a bright green) that is supposed to be gray.
  • If the game is edited so the Rings display correctly, they will also be green.
  • Tails cannot be harmed by spikes.

Marble Zone (Chemical Plant)

Too many transportation pipes, someone help me...

The only other Zone seen during the game's Nick Arcade appearances, the CPZ gameplay demo was visible in the background of several shots. Until the ROM was dumped, it was the only glimpse of its differences.

Nick Arcade proto Simon Wai proto
Sonic2ChemicalPlantBGNick.png Sonic2ChemicalPlantBGWai.png
  • The background (which does not animate and has only one layer of scrolling) has a pink tint rather than olive-green, which was probably changed to make CPZ feel more industrialized than it does here.
  • A few of the buildings are different - this mostly applies to the ones made of rectangular lights, which are short and wide at this point but tall and thin in all other known prototypes.
  • The bottom section has more changes, with the Nick Arcade background having a lot more steel beams and a conspicuous absence of those square blue lights seen in the other builds. The Nick Arcade background reuses a few of the transportation tube tiles in the bottom-left corner.
  • The background seen in other versions is 128 pixels taller than the one in this build. It's all for nought, though, since the stage isn't tall enough in either build to see the bottom of the background. They might have been planning to change the vertical scrolling speed of the background, but it's the same speed in all known versions of the game.

Act 1

Full Maps
Nick Arcade proto
Simon Wai proto
Nick Arcade proto Simon Wai proto
Sonic2ChemicalPlant1Section1Nick.png Sonic2ChemicalPlant1Section1Wai.png
  • The layouts between versions are so different that they're not easily comparable, but the start of the Act stayed pretty much the same. The line of three rings was moved to the top of the rightmost platform and another vertically-moving platform was added.
Nick Arcade proto Simon Wai proto
Sonic2ChemicalPlant1Section2NickProto.png Sonic2ChemicalPlant1Section2WaiProto.png

This section was slightly extended.

  • There was originally a short section in the upper path under the moving platform which would lead to a transportation tube. The section itself later got removed in the Simon Wai prototype.
  • Two Super Ring monitors and a moving platform were removed.
  • If Sonic gains enough speed by doing a spindash, he can get to the top of the stage. This obviously wasn't a problem here in Nick Arcade, due to the speed cap. This was later fixed in Simon Wai by filling the chunks above.
Nick Arcade proto Simon Wai proto
Sonic2ChemicalPlant1Section3NickProto.png Sonic2ChemicalPlant1Section3WaiProto.png
  • The transportation tube has been moved to the left.
  • The speed booster trap got changed into a red spring farther away from the section.
  • Interestingly, this transportation tube was supposed to lead into a different area, in which it was later completely revamped by Simon Wai on-wards.
  • Solid walls and slopes were added to make the level more comfortable with high speeds.
Nick Arcade proto Simon Wai proto
Sonic2ChemicalPlant1Section4NickProto.png Sonic2ChemicalPlant1Section4WaiProto.png

This area was almost completely revamped.

  • The only parts that remained unchanged was a transportation tube on the lower path and some floor chunks above it.
  • There are the total of three transportation tubes in one area, which is a bit too much. It was later changed to one transportation tube only.
  • Slopes, and more floor chunks were added to make this area less bland. Though, it's still empty however.
Nick Arcade proto Simon Wai proto
Sonic2ChemicalPlant1Section5NickProto.png Sonic2ChemicalPlant1Section5WaiProto.png
  • The transportation tube was moved further in the level.
  • This area is also completely different, with a scrapped lower path underneath it.
  • In Simon Wai, there is a speed booster underneath the ground. Interestingly, it contains the exact same position as the speed booster chunk in Nick Arcade. Proving that at least some work was done before the section was scrapped.
  • An extended section involving the bubble launchers was added.
Nick Arcade proto Simon Wai proto
Sonic2ChemicalPlant1Section6NickProto.png Sonic2ChemicalPlant1Section6WaiProto.png
  • This section have been moved slightly further into the level.
  • There are the total of four transportation tubes, which again, is a little too much. Simon Wai on-wards, there is only one transportation tube.
  • The blue chemical pipes have been extended in order to bring more speed. This ended up replacing the second and third transportation tubes.
  • The upper route is completely different.
  • A yellow spring was added and a platform has been added underneath, along with some more slopes towards it.
  • A speed booster has been removed, and the chunk near the second speed booster have been changed to flat ground.
Nick Arcade proto Simon Wai proto
Sonic2ChemicalPlant1Section7NickProto.png Sonic2ChemicalPlant1Section7WaiProto.png
  • There's 14 rings at the top path, with Simon Wai moving half of them over to the loop in the middle path.
  • The upper loop leads to a different section, but both of those sections are present in later layouts, it's just a matter of different paths.
  • Most of the upper section has been slightly moved to the right, aside from the tubes, which are completely different.
  • There are two transportation tubes in the Nick Arcade prototype, with Simon Wai removing one of them. The remaining transportation tube was moved further to the right.
Nick Arcade proto Simon Wai proto
Sonic2ChemicalPlant1Section8NickProto.png Sonic2ChemicalPlant1Section8WaiProto.png

This point on forward, there are no rings whatsoever.

  • The upper path has been completely removed.
  • A speed booster has been moved upwards, fitting better with the layout on the lower path.
  • A section below the pipes were removed, due to it being overall useless.
Nick Arcade proto Simon Wai proto
Sonic2ChemicalPlant1Section9NickProto.png Sonic2ChemicalPlant1Section9WaiProto.png
  • Twelve rings have been added to the loops.
  • The section above is a bit empty in Nick Arcade, Simon Wai filled the gap by adding more solid ground and chemical pipes.
  • Another speed booster was removed, and the other speed booster was moved and changed it's direction towards the loops.
  • Two transportation tubes in Nick Arcade are present, one in the upper path, and other in the lower path. Simon Wai later removed the lower transportation tube.
  • Two of the three connected transportation tubes were removed. However, seems like they couldn't figure out where to lead it to, since the transportation tube leads to itself accordingly.
Nick Arcade proto Simon Wai proto
Sonic2ChemicalPlant1Section10NickProto.png Sonic2ChemicalPlant1Section10WaiProto.png
  • There are two transportation tubes in the Nick Arcade prototype, with Simon Wai having the lower transportation tube replaced with a upwards slope.
  • The upper section has been completely removed.
  • A speed booster trap was removed.
  • The middle section was slightly wider in the Nick Arcade prototype.
  • A chemical slope pipe was changed to flat ground.
  • The second bubble launcher in the lower path is now lower.
Nick Arcade proto Simon Wai proto
Sonic2ChemicalPlant1Section11NickProto.png Sonic2ChemicalPlant1Section11WaiProto.png
  • Three transportation tubes total are present in the Nick Arcade prototype, which you guessed it, is way too much. Simon Wai removed all except one.
  • The two transportation tubes were replaced by a new section.
  • Fourteen rings were added on the loops.
Nick Arcade proto Simon Wai proto
Sonic2ChemicalPlant1Section12NickProto.png Sonic2ChemicalPlant1Section12WaiProto.png
  • Five rings were added on the loop.
  • They really liked transportation tubes in Nick Arcade, having three transportation tubes all in one area. Simon Wai removed all of them this time around.
  • The lower path was extended to link with the middle path, replacing the same two transportation tubes in the process.
  • Most of ground were replaced with chemical pipes.
  • The lower section underneath the second loop was removed entirely.
Nick Arcade proto Simon Wai proto
Sonic2ChemicalPlant1Section13NickProto.png Sonic2ChemicalPlant1Section13WaiProto.png
  • The bottom section has been extended, with a whole new loop and slopes in place.
  • Five rings were added on the newly placed loop.
  • An even lower section were removed.
  • A chemical pipe at the upper path got extended to link the middle section together.
  • The chemical pipe in the bottom section has been changed slightly to reflect the removal of the lower path underneath.
  • An extra bubble launcher at the upper path got replaced with a chemical pipe.
Nick Arcade proto Simon Wai proto
Sonic2ChemicalPlant1Section14NickProto.png Sonic2ChemicalPlant1Section14WaiProto.png
  • Again, there are three transportation tubes in Nick Arcade, with Simon Wai removing all of them except for just one.
  • Alternatively, the transportation tube that remained was moved a single chunk to the right.
  • The entire upper section was removed, but the concept was later reused in Simon Wai's Act 2.
  • The middle section is still here, though it's completely different.
Nick Arcade proto Simon Wai proto
Sonic2ChemicalPlant1Section15NickProto.png Sonic2ChemicalPlant1Section15WaiProto.png
  • The chemical slope pipe at the upper section got removed. It's likely that there was supposed to be a staircase here, but it hasn't been implemented yet.
  • There's no signpost present. If it were to be placed, there would be almost no space for the signpost considering the current layout.


  • There are a few more objects on the upper path, but they stop appearing halfway through the stage. This includes the path swapping objects that make the intersecting tubes and loops work.
  • The bubble launchers are in place, but the bubbles themselves are not implemented yet.
  • Transportation tubes do not function properly, letting Sonic fall out to the floor/pit below. However, the way they're laid out show that you may have had to run into the transport tube machines to go through them rather than break open a tube to enter.
Nick Arcade to CENSOR builds Beta 4 onward
Sonic2WaiProto CPZLoop.png Sonic2 CPZLoop.png
  • The loops have their early hexagonal corners, which made it to the CENSOR prototype before being changed in Beta 4.
  • Acts 2 and 3 are identical in layout to Act 1, indicating that there wasn't much work completed at this point. They use the same ring layouts as GHZ Acts 2 and 3.
  • While it hasn't been coded yet, there's art for the Chemical Plant boss in the ROM.
  • Some objects from the Sonic 1 Marble Zone are accessible via Debug Mode, albeit with corrupted tiles.
  • Playing this Zone after Green Hill will keep the broken art from GHZ, but with a different palette.

Spring Yard Zone (Hidden Palace)

This...is beautiful.

Perhaps the most interesting Zone that was cut.

  • Act 1 seems to have been worked on while the monitors were still using their Sonic 1 mappings, as there is a Tails 1-Up monitor early in Act 1. The shield monitor would also be a ring monitor if converted to Sonic 2's mappings.
  • There are dinosaur and bat badniks present here.
  • Various unused badniks can be placed with Debug Mode, including the piranha, Stego, Gator, early Octus, and early Aquis. Most have glitched sprites, although Pro Action Replay code 01C1D8:0007 will fix most of their graphics.
  • If Sonic makes a precise short jump while rolling fast enough on the green platform after the first tube, he will clip under the platform after the second Redz, and fall into the submerged section of ground underneath. This was not fixed in any later builds.
  • The bubble sprites use the wrong graphics.
  • There is an emerald object which blocks a pipe to nowhere in Act 1. Many thought this was the Master Emerald due to being a large green emerald in a Zone called Hidden Palace, but it was actually supposed to be a breakable object like the rocks in Hill Top.
  • If Sonic rolls into the emerald, he'll drop into the pipe below it. This was fixed by the Simon Wai build.
  • If normally playing Act 1, it stops prematurely due to a slope which is far too steep to climb. If you use Debug Mode to go past it, there's a little more to see, including a non-functioning water slide.
  • Most of the Debug Mode objects have broken previews. The ones that don't are the ring, monitor, loop point, and dinosaur.
  • Similarly to Green Hill, the palette has one wrong color (a bright green that is gray in all other levels). However, nothing uses the single wrong color here.
Nick Arcade proto Simon Wai proto
Tails is a bee, I guess? Cool and good.
  • The players' underwater palette is the same as in Labyrinth Zone in Sonic 1. This obviously works fine for Sonic, but Tails has some serious problems.
The proper underwater palette, matching the one seen in the Simon Wai prototype, is in the ROM at 0x0027A2. However, the game is still using Sonic 1's logic for loading the underwater player palette: If the Act number is 03, it loads palette 10 (Labyrinth Zone 4, aka Scrap Brain 3), otherwise it loads palette 0F (Labyrinth Zone 1-3). So, the intended underwater player palette is overwritten.
  • If you let the drowning countdown begin then jump out of the water, Labyrinth Zone's music will play.
  • Acts 2 and 3 have not been worked on. Act 2 recycles object placement from GHZ Act 2 and Labyrinth Act 2's water levels, while Act 3 uses GHZ Act 3's object placements.
  • Player 2 can control the water level in Act 1 by pressing Up or Down.
  • The boss music plays in Act 3 if the camera moves past X coordinate $2BFF, but there is no boss.
  • Tails acts like he is on land while he is in water. Because of this, his movements are not slowed down and he cannot drown.

Labyrinth Zone

What was this intended to be...?

Uses Chemical Plant's tiles, Labyrinth's rippling, Marble's ring layouts... and it's completely broken, due to trying to use the Green Hill Zone chunk format. It is unknown what this level slot was going to be used for before they re-arranged the level IDs but it is often speculated that it might have been for Oil Ocean (as it was one of the first zones to be worked on), Metropolis (again, one of the first zones to be worked on), Death Egg, or Genocide City.

  • While there are some strips of "land" (garbage data), it is otherwise like Genocide City and Death Egg in the Simon Wai and August 21 builds.
  • If you enter Marble Zone first, the game partially loads the layout for that level, regardless of the act.
  • The boss music plays in Act 3 if the camera moves past X coordinate $1C9F, but like in Hidden Palace, there is no boss.

Star Light Zone (Emerald Hill)


The most complete Zone in the prototype, and the only one playable without using the Level Select. On Nick Arcade, contestants played Act 1 and had to collect 25 rings in 30 seconds.

This Zone features a badnik that was removed from the final version: a red-shelled snail. This Motobug-like enemy slowly moves around on the ground. When it sees the player, it charges at them (as much as a snail can charge at something, anyway). This enemy was replaced by Coconuts in the final game.

This Zone also has partially unused lines of parallax scrolling, which can be found by placing random blocks in chunks above the clouds and little hills in the background. They don't scroll, unlike other parts of background.

Clouds1.png Clouds2.png

It's possible this is evidence that the clouds from early mockups were in the game at some point, but were replaced with the final graphics.


Act 1

Full Maps
Nick Arcade proto
Simon Wai proto
Nick Arcade proto Simon Wai proto
Sonic2EmeraldHill1Section1Nick.png Sonic2EmeraldHill1Section1Wai.png
  • In the Nick Arcade prototype, it's impossible to get back to the upper path once you fall down into the lower path. To fix this, the terrain on the lower path was raised a bit in the Simon Wai prototype, making it possible to reach the moving platform.
    • The three-ring line was not erased, so it's now embedded in the newly-raised floor.
  • There's a spike pit with a big moving platform that was completely removed from the final version, probably because it's a little early in the game to introduce something like that.
  • The cliff in the top-middle was raised as well, making the second floating platform more useful.
  • There are more spikes in the Simon Wai prototype: two below the first large floating section, and another one in the middle of the two that were in the Nick Arcade prototype.
  • The red spring at the bottom-right was removed after this prototype.
Nick Arcade proto
Simon Wai proto
  • The upper path is considerably simpler in the Nick Arcade prototype, which just consists of a few jumps over relatively simple terrain. In the Simon Wai prototype, this has been changed to add a piece of ground above the waterfall section, which is easiest to reach by using the new yellow spring to the left. The upper path also contains the first long quarter-pipe section in the Simon Wai prototype.
    • Note that the enemy placement in the Simon Wai prototype is a bit sloppy, especially in regards to the Buzzer enemies. The Buzzer on the top path seems like it might pose some problem to the player in the Nick Arcade prototype, but with the new layout, it's just placed oddly at the top of the quarter-pipe.
  • In the lower path, there's a red spring to the right of the Snail enemy. With the other spring in the previous section, this completes the first of the game's spring traps. This was thankfully removed from the final game.
  • Again, the ground on the lower path in the Nick Arcade prototype is flatter than the ground in the Simon Wai prototype. It's a bit emptier in the Simon Wai prototype, though - there are three rings that were deleted from the Nick Arcade layout.
Nick Arcade proto
Simon Wai proto
  • In the Nick Arcade prototype, if the player goes at full speed on the corkscrew path section, they'll just drop off into the top of the first waterfall seen here. The Simon Wai prototype changes this by adding a small quarter-pipe section that leads to a group of eight rings.
  • In the lower path, a diagonal yellow spring was removed in the bottom-left and the three rings were moved more to the right.
  • The Simon Wai prototype adds a new upper path to the right of the yellow spring by adding a floating section and adding more ground above the second right-facing yellow spring.
    • Again, the Buzzer enemies haven't been adjusted to the new layout yet, so their position no longer makes sense.
Nick Arcade proto Simon Wai proto
Sonic2EmeraldHill1Section4Nick.png Sonic2EmeraldHill1Section4Wai.png
  • The way to get to the floating platforms in the upper path was changed between prototypes.
    • In the Nick Arcade prototype, the player has to either jump to the right from the top of the big quarter-pipe or spin-dash up the quarter-pipe if they fall down.
    • In the Simon Wai prototype, the player can just use the yellow spring to jump to the platform.
  • The hidden path in the middle of this section was also changed between versions. It works properly in the Nick Arcade prototype, but in the Simon Wai prototype, the player can only get to the third ring before they hit a solid wall. Note that each prototype actually has the same number of rings, they're just covered up more in the Simon Wai build.
Nick Arcade proto Simon Wai proto
Sonic2EmeraldHill1Section5Nick.png Sonic2EmeraldHill1Section5Wai.png
  • The slope below to the right of the spikes on the lower path was changed to a small quarter-pipe in the Simon Wai prototype, and the solid block above said slope was changed as well. This seems to have been done to set up the path seen in the final version, but in the Simon Wai build it doesn't actually amount to much.

Act 2

Full Maps
Nick Arcade proto
Simon Wai proto
Nick Arcade proto Simon Wai proto
Sonic2EmeraldHill2Section1Nick.png Sonic2EmeraldHill2Section1Wai.png
  • There are only 13 rings here in the earlier prototype, compared to 25 in the later prototype. The Simon Wai prototype adds four rings above the wooden bridge, removes the three-ring line in the upper-left, takes away one of the rings from the four-ring string in the middle-left, and adds a large 12-ring group in the upper-right.
  • The diagonal yellow spring was horizontally flipped and moved to the right in the Simon Wai prototype as part of the aforementioned ring change.
  • A pair of spikes were added to the left of the Snail enemy. Be careful with that spring!
Nick Arcade proto Simon Wai proto
Sonic2EmeraldHill2Section2Nick.png Sonic2EmeraldHill2Section2Wai.png
  • An extra ring was added to the string above the lowermost wooden bridge.
  • The four rings far above the topmost bridge were moved down to be just above it in the Wai build.
  • The yellow spring and the two rings associated with it were removed.
  • The horizontal moving platform was replaced with an extended cliff section.
Nick Arcade proto Simon Wai proto
Sonic2EmeraldHill2Section3Nick.png Sonic2EmeraldHill2Section3Wai.png
  • The three-ring string above the spikes in the lower path was moved to above the spikes in the upper path. Hooray!
  • As is tradition, four rings were added above the wooden bridge in the lower path.
  • The spikes on the lower path were moved more to the right.
Nick Arcade proto Simon Wai proto
Sonic2EmeraldHill2Section4Nick.png Sonic2EmeraldHill2Section4Wai.png
  • The entrance to the 1-Up monitor is a bit more conspicuous and a little less easy to just fall into in the Simon Wai prototype.
  • The up-left diagonal spring was moved a bit more to the right for...some reason.
  • The two rings above the Buzzer were deleted, and a group of seven rings was added in the path of the up-right diagonal spring.
  • The lower path is much more treacherous in the Simon Wai prototype, with a lot of added spikes, both stationary and retracting.
  • The yellow spring on the ground is now a red spring in the ground.
  • There are only three rings above the lower wooden bridge in the Nick Arcade prototype. That's not four rings!!!
Nick Arcade proto
Simon Wai proto
  • The layout of this section was greatly changed by the time of the Simon Wai build. All of the yellow springs were removed, including the first up-left diagonal spring that leads to a tunnel that dumps out to the extra life monitor in the previous section.
  • In the Nick Arcade prototype, the tunnel that goes to the super ring monitor leads to a dead-end. In the Simon Wai prototype, the layout was adjusted so the player doesn't have to double back to the left.
  • The upper path is a little easier to reach in the Simon Wai build, and the upper path has also been raised up.
  • The super ring monitor was changed to an Invincibility monitor.
  • Falling platforms and Chompers were added to the waterfall section, and the Buzzer was removed.
  • Speaking of Buzzers, their sloppy placement is most evident here. Again, they make sense in the earlier prototype's layout, but in the Simon Wai prototype, one of them is partially embedded in the ceiling!
  • A single set of retracting spikes was added in the lower path.
  • A diagonal up-right spring was added below the start of the corkscrew path above this section. This spring leads to the top of the loop in the next section...
Nick Arcade proto Simon Wai proto
Sonic2EmeraldHill2Section6Nick.png Sonic2EmeraldHill2Section6Wai.png
  • ...The loop, by the way, which is placed further up and to the left in the Simon Wai build, and is now fused with the platform at the end of the corkscrew section.
  • It's possible to get to the top of the loop from the bottom path by using the vertical moving platform in the Nick Arcade prototype. This is no longer possible in the later builds.
  • The section of the ground to the left of the falling floating platforms has more flowers and spikes in the Simon Wai build.
  • The underground section extends further to the right in the Nick Arcade prototype.
  • The yellow spring at the bottom was moved to the right and in the ground in the Simon Wai prototype, and more spikes were added to its left.
  • A Shield monitor was added at the end of the tunnel in the lower path.
  • The tunnel no longer exits to a wooden bridge with rings and Chompers in the Simon Wai prototype. This was changed to a pit and...nothing else, really.
Nick Arcade proto Simon Wai proto
Sonic2EmeraldHill2Section7Nick.png Sonic2EmeraldHill2Section7Wai.png
  • Remember the up-left diagonal spring on that loop? In the Nick Arcade prototype it leads nowhere in particular, but in the Simon Wai prototype, it leads to a new floating section with a 1-Up monitor. There's an additional floating platform down and to the right, but there's nothing on it.
  • The super ring monitor was removed.
  • These emerald hills weren't hilly enough in the earlier prototype, so the small quarter-pipe was enlarged (and six rings added), another small quarter-pipe was added, and the ground to the right of that quarter-pipe was elevated.
  • The two snail enemies on the lower path were removed, and eight rings were added.


Nick Arcade proto Simon Wai proto
Sonic2GHZLightNick.gif Sonic2GHZLightFinal.gif
  • The animated cave tiles flash rapidly in the Nick Arcade prototype. They're at their final animation speed starting in the Simon Wai prototype.
  • This also applies to the tiles in Hill Top Zone.
  • Emerald Hill's debug object list includes Hill Top's seesaw platform, although it sees no use here in either Act.
  • This is the only Zone with a stage boss in both the Nick Arcade and Simon Wai prototypes.
  • Tails is absent; considering Sonic loses rings when Tails gets hit, this was very likely done to help the players on Nick Arcade. He's present from the Simon Wai build onward.
  • Spikes that hang from the ceiling don't hurt Sonic if he jumps up to touch them. If you use Debug Mode to hit them from the top, they will damage Sonic, suggesting that the only difference between the ceiling and floor spikes is that the graphics are vertically flipped. They work properly in the Simon Wai prototype.
  • The boss fight is similar to the final game's, but has several minor changes:
    • In both versions, Eggman's vehicle is already parked on the spot instead of entering from the right.
    • The arena seems to have originally been wider, given that Eggman doesn't return from the left side until far later.
    • If the boss is facing left when it finishes exploding, it will change direction and face right as Eggman begins to escape.

Scrap Brain Zone (Hill Top)

This is clearly not technological.

A preliminary version of Hill Top. Due to occupying the former Scrap Brain level slot, there's a bit of residual weirdness. Read on for more about that.

Act 1

Full Maps
Nick Arcade proto
Simon Wai proto

Act 1's layout is complete, but the lower screen bound has not yet been changed from Sonic 1's SBZ Act 1. As a result, the Act cannot be finished.

Nick Arcade proto Simon Wai proto
Sonic2HillTop1Section1Nick.png Sonic2HillTop1Section1Wai.png
  • One ring was removed from the start of the stage, and the layout was changed from a downhill slope to a flat strip of land.
Nick Arcade proto Simon Wai proto
Sonic2HillTop1Section2Nick.png Sonic2HillTop1Section2Wai.png
  • The rising and lowering platforms in the lava are placed higher up in the Simon Wai prototype.
  • The pit with the first seesaw platform was removed from the Simon Wai build's layout.
  • The up-right red spring that leads to the upper tunnel isn't present in the Nick Arcade version.
  • A set of spikes was added below the rightmost set of rings in the lower path.
Nick Arcade proto Simon Wai proto
Sonic2HillTop1Section3Nick.png Sonic2HillTop1Section3Wai.png
  • There are no rings in the tunnel section yet, and the seesaw platforms and up-right springs aren't here yet either.
  • The four rings above where the seesaw will be were deleted, and three rings added to the right of the 1-Up monitor.
  • A set of spikes were added to the right of the small quarter-pipe.
Nick Arcade proto Simon Wai proto
Sonic2HillTop1Section4Nick.png Sonic2HillTop1Section4Wai.png
  • Besides the super ring monitor, there are no rings in this section of the Nick Arcade build.
  • Again, the up-right yellow spring isn't present yet.
  • The ground above the second seesaw was lowered in the Simon Wai prototype, making it a tad easier to get up to.
  • The third seesaw was moved from below the lift platform to the nasty lava pit. Some spikes were added to the pit's ceiling. Thanks.
  • The lift platform is a few pixels too low in the Nick Arcade version, so it doesn't properly line up with the guide line.
Nick Arcade proto Simon Wai proto
Sonic2HillTop1Section5Nick.png Sonic2HillTop1Section5Wai.png
  • From this point on, the only objects in the Nick Arcade prototype are those that the player absolutely needs to complete the stage, which includes seesaws and lifts.
  • Other than being mostly void of objects, the layouts are identical here.
Nick Arcade proto Simon Wai proto
Sonic2HillTop1Section6Nick.png Sonic2HillTop1Section6Wai.png
  • Since the Nick Arcade prototype only has one subtype for the lift platforms, the one that is supposed to be facing left is facing right and goes straight into the ground.
Nick Arcade proto
Simon Wai proto
  • The seesaw platform was replaced by a red spring.
  • In the Simon Wai prototype, starting at this point, the layout is several blocks longer than the earlier prototype. This was done due to the newly-added rising ground/lava section. To keep the player from going back once the rising starts, several one-way barriers had to be added. So, the layout was extended by a few blocks and the ceiling was lowered.
Nick Arcade proto
Simon Wai proto
  • The same changes can be seen here. The pit was widened as well.
Nick Arcade proto Simon Wai proto
Sonic2HillTop1Section9Nick.png Sonic2HillTop1Section9Wai.png
  • There's a small tunnel section at the top-left corner of this area in the Nick Arcade prototype. Replaced by a solid wall in the Simon Wai version.
  • The seesaw platform is further in the ground in the Simon Wai prototype.

Act 2

Full Maps
Nick Arcade proto
Simon Wai proto

Act 2 cannot be completed with Sonic, because if the camera moves past X coordinate $1EAF the game tries to load pattern cue $1E, referencing data that is not a pattern load cue, causing the game to read garbage art data as a pointer and subsequently crash with a blue screen. As the event handler is specifically looking for Player 1's camera X position to trigger the event, however, Tails can complete the Act. Alternatively, you can use the PAR code 007B0A:7000 to study the act.

Removing the art load cue will allow Sonic to go further into the level. After the point that triggered the art cue is reached, the player can fall off the level to go to Act 3, a remnant from Scrap Brain Act 2 in Sonic 1.

Nick Arcade proto Simon Wai proto
Sonic2HillTop2Section1Nick.png Sonic2HillTop2Section1Wai.png
  • Unlike Act 1, there are absolutely no objects here in the Nick Arcade prototype, so we're just comparing layouts at this point.
  • The ground at the start drops down in the Nick Arcade prototype, and the lava is lower as well. The player would probably jump on a spring to get up in the earlier layout, as opposed to the seesaw platform seen in the Simon Wai build.
  • The long slope down to the lower section seen in the Simon Wai layout is broken up by a small quarter-pipe in the Nick Arcade build. After falling to the lower path, it's impossible to get back up, which is probably why it was changed in the later prototype.
Nick Arcade proto Simon Wai proto
Sonic2HillTop2Section2Nick.png Sonic2HillTop2Section2Wai.png
  • Well, the Nick Arcade layout is obviously using the wrong blocks here. This was thankfully fixed in the Simon Wai prototype.
Nick Arcade proto Simon Wai proto
Sonic2HillTop2Section3Nick.png Sonic2HillTop2Section3Wai.png
  • The platforms and guiding lines for the lifts are higher up in the Simon Wai prototype. If there actually was a lift object in the Nick Arcade prototype, it would clip into the loop below, which is obviously not something you'd want.
Nick Arcade proto Simon Wai proto
Sonic2HillTop2Section4Nick.png Sonic2HillTop2Section4Wai.png
  • As in Act 1, the stage is slightly wider to accommodate for the newly placed one-way barriers.
Nick Arcade proto Simon Wai proto
Sonic2HillTop2Section5Nick.png Sonic2HillTop2Section5Wai.png
  • The same change can be seen in the paths below. The lowermost path opens up earlier in the Nick Arcade prototype.
Nick Arcade proto Simon Wai proto
Sonic2HillTop2Section6Nick.png Sonic2HillTop2Section6Wai.png
  • In addition to the standard layout widening, the Nick Arcade prototype uses the wrong blocks for two of the ceiling pieces. These might be remnants of an even earlier Hill Top layout.
Nick Arcade proto Simon Wai proto
Sonic2HillTop2Section7Nick.png Sonic2HillTop2Section7Wai.png
  • The last of the many widening-related layout changes. Oh, and the second floating platform was removed.
Nick Arcade proto Simon Wai proto
Sonic2HillTop2Section8Nick.png Sonic2HillTop2Section8Wai.png
  • The upper path at the end of the stage extends all the way up to the upper bounds of the level in the Nick Arcade prototype, which is a little much. Two of the cliffs and their accompanying guiding lines, as long as one long floating platform, were removed from the Simon Wai layout.
Nick Arcade proto Simon Wai proto
Sonic2HillTop2Section9Nick.png Sonic2HillTop2Section9Wai.png
  • The cliff at the start of the final cave section was lowered in the Simon Wai build.

Act 3

Look guys, it's Genocide Ci-*shot*
  • In Sonic 1, Scrap Brain Act 3 is another Labyrinth Zone level, or a "Labyrinth Act 4" if you will. As previously mentioned, Labyrinth in this build is broken and uses Chemical Plant's graphics, so this level follows suit.
  • The exit to Final Zone is still present, and can be activated by hugging the top of the level and moving to the right via Debug Mode.
  • The palette is a combination of the one from Scrap Brain Act 3 and the cycling colors from Chemical Plant.
  • Act 3, if accessed through Act 2 by the ways listed above, will not be empty like Labyrinth Zone. Instead, it'll have a layout consisting of garbage data and Chemical Plant graphics.


  • While the parallax scrolling has been mostly implemented, the clouds (or whatever they are) in the background don't move on their own yet. The blue mountains far in the back don't scroll yet, either.
  • The lifts don't drop at the end of their path, and there is only one subtype: The one seen at the start of Act 1. They always move to the right and always stop at the same point.
  • The lava cannot harm you because the actual damage objects haven't been placed yet.
  • The debug object list includes the Buzzer, Snail, and Masher from Emerald Hill. Only the Masher doesn't have its graphics overwritten.
  • The seesaws copy the center green orb for the weight instead of a flameless Sol, an element seen in a Sega Visions magazine preview:
Nick Arcade Simon Wai onward
Innocent enough... Seizure potential: Moderate

Final Zone

Time to beat the Eggman, right? Uh...no.
  • Hill Top's graphics are used. Sonic 1's Final Zone uses Scrap Brain's graphics, so this is unsurprising.
  • Going left drops you over an edge to a dead end.
  • If the camera moves past X coordinate $2147, the game crashes with a purple screen. This is because the game tries to load the art for the final boss by loading art cue $1F which does exist, but references data that is not a pattern load cue, causing the game to read garbage art data as a pointer and lock up.
  • Through hacking to disable the art load request, it is possible to go further into the Zone (PAR 007B66:7000). The Sonic 1 final boss' object number will load, but the boss' code is gone and replaced with a dummy object. Because of this, there's nothing to fight and hence no way to reach the "ending".
  • The level layout is actually that of Hill Top Act 1, with no rings or objects (which is odd considering Sonic 1 used the layout of Act 2). Playing past the point where Act 1 would normally end will simply lead you to a pit. Going past the pit with Debug Mode will lead to a large void before the beginning of the level layout loops over.
  • Beating the level by hacking a signpost into it sends you to the Sega screen. This is consistent with Sonic 1, as the ending could only be triggered by beating the boss. Even if the boss was implemented, it would then crash due to the ending "screen" not existing anymore.

Ending Scene (Zone ID 06)

By using Action Replay code FFFE10:0600 you can access Zone ID 06, which was the ending scene in Sonic 1. The stage uses Final Zone's music, Green Hill's art and palette, and Chemical Plant's layout.

Unfortunately, it's also very much broken: The stage is mostly garbage data still left over in the ROM, some collision is present, and some pattern load cues must be modified or else the game will crash with a blue screen when starting the level. Green Hill's chunk compression and level header also must be used here to prevent a crash. Trying to access Acts 2 or 3 of this Zone will result in an Illegal Instruction error.

Special Stage

The game crashes while loading it due to bad pointers and missing art, but most of the code is based on the Sonic 1 Special Stage.

It is possible to modify the code to where it won't crash, and doing so reveals that the graphics have been deleted from the ROM. The color palettes still work, though, and the coding for all objects is still present.