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Proto:Super Mario Kart/kart *

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This is a sub-page of Proto:Super Mario Kart.

This article is a work in progress.
...Well, all the articles here are, in a way. But this one moreso, and the article may contain incomplete information and editor's notes.
To do:
  • Info on debug mode (accessed by pressing Start+Select on the title screen, seems to be similar if not identical to the one found in mario-kart-*
  • Add exact instructions on how to fix debug menu crashes. Fixes are known, but not documented here yet.
  • Check for unused data in the rom.
  • More screenshots.
  • Finish track differences.

A later build than April 13 build, and very similar to the unreleased prototype, though it still has some differences. The ROM has a timestamp of May 18, 1992, and is in English, unlike the earlier April 13 build.

The build is actually split into two files: kart_01 and kart_02. To get the build working, append kart_02 to the end of kart_01 and then apply this patch.

Changes between this and earlier build


  • The small demos seen while sitting on the title screen are now added in.
  • The fourth place ending is now implemented.
  • The tracks are now in their final order.
  • The unique 2nd and 3rd place ending cutscenes have been swapped around, and have small changes in the animation.


  • Battle Course 4 (Battle Course 1 in this build) now takes place in Mario Circuit.
  • Computer opponents now use character specific items. They now throw items ahead too.
  • The player can now hop with L and R.
  • Choco Island 3 has now been replaced by Rainbow Road.

Graphics / UI

  • Luigi now uses Mario's body graphics.


  • Title screen uses it's proper theme.
  • Mario Circuit, Choco Island, Ghost Valley, Bowser's Castle, and Battle Mode now have their proper themes.
  • The 2nd-4th place jingle has been finalized.
  • The Game Over jingle has been added.

General Differences

  • The logo is still based on the Japanese version. The background already got updated to the international version, by removing the Japanese text.
  • You cannot navigate the menus using select, unlike the final version.
  • The cup selection screen lacks an orange border as well as showing which cc you've chosen.
  • Everything is locked from the start, unlike the earlier prototype.
  • Course Select is misspelt as Course Selct in the course selection screen.
  • Time Trial ghosts are not implemented yet
  • The replay system in Time Trial is not implemented yet.
  • During the result/score tally screen, the CPU that don't manage to finish in time get an "OUT" instead of their time like the final.
  • The coin UI does not flash yet when having 0 coins. You still spin out when touching racers while having 0 coins, however.
  • Before receiving your first item the item roulette space shows 1p and 2p, which was changed to just 1 and 2 in the final.

Gameplay Differences

  • You start with 4 coins instead of 5 in the final.
  • You start out with 2 lives instead of 3 in the final.
  • Starting boost or motor burn at countdown is completely missing.
  • Falling into the lava, water, or of the map doesn't give a coin penalty. Oddly enough this is present in the earlier prototype from April 13, 1992.
  • Moles do not attach on you; instead, you just spin out.
  • Cheep-Cheeps and Piranha Plans will cause you to lose coins when you touch them.
  • You can still lose coins after you've finished and bonk into someone.
  • Drifting in circles does not eventually spin you out. This worked fine in the earlier April 13, 1992 proto. This was perhaps due to the drift mechanic being changed.
  • You do not get an extra life after you've finished first three times.
  • The CPU appears to not be able to get hit by dropped bananas, as well as items fired by other CPU's. As a result, you never see other CPU players getting hit on the minimap way behind you while playing, unlike the final.
  • The CPU doesn't attempt to avoid you yet, creating situations sometimes where they bonk endlessly into you. This is especially common when a character with a lighter weight than yours rams into you from behind.
  • Special Cup is now locked by default in Time Trial, but the button code to unlock it hasn't been implemented yet.
  • The mud in Choco Island is more slippery when driving on it.
  • Toad and Koopa Troopa lack the special sharp skidding ability that can be performed in courses like Mario Circuit, Ghost Valley and Bowser's Castle. Their skidding is the same as the other characters.

Bugs / Issues

  • Rainbow Road has the graphics missing for the position counter, thus crashes when the final lap is reached, making it incompletable. This makes completing 100cc currently impossible. This is fixed by this patch by MrL314.
  • In Battle Mode, going out of bounds using a feather causes you to become permanently stuck, similar to the undumped prototype. Lakitu will carry the player far away from the map, and will eventually place down and pick up the player in an endless loop. This is due to the checkpoint targets pointing to an area far out of bounds in the upper left corner of the map. Oddly enough this works completely fine in the earlier prototype from April 13, 1992.
  • When Lakitu pulls you over the finish line, the lap won't count.
  • When racers finish before you do they often don't cheer or have their position flashing, due to unknown reasons. This once again works fine in the earlier April 13, 1992 build, however, where it flashes normally until position 4 at all times, like the final.
  • The player will slow to a crawl after finishing the race in Time Trials.
  • Finishing a race while hopping makes you float in the air.
  • On rare occasions, the tires on Luigi's kart continue to spin even when he remains idle.

SMK MayProto LuigiGlitch.gif

Item Differences

  • Lightning does not really cause the AI to slow down.
  • Characters made small by Lightning cannot be squished.
  • Touching bananas put you on full stop like green shells.
  • Going over an obstacle like pipes and Piranha Plants with a star make you feather jump instead of destroying it.
  • Bananas can't be thrown forward and shells can't be dropped.

Sound Differences

Ghost Valley

Proto Final

Played in a lower tempo.

Peach's Theme

Proto Final

The sampling for the bassline was changed.

Yoshi's Theme

Proto Final

Played in a lower tempo.

Donkey Kong Jr.'s Theme

Proto Final

Uses the same melody as the April 13, 1992 build. This time however, it uses a simpler drumbeat.

Award Ceremony

Proto Final (4th Place)

The theme used when you get rewarded your trophy has a completely unique theme. It sounds very similar to the 4th place ending theme heard in the final game.

Other Sound Differences

  • Rainbow Road plays Bowser's Castle's music, as the final Rainbow Road music has not been added to the game yet.
  • The Vanilla Lake theme is the same as the April 13, 1992 build, as opposed to the seemingly later undumped prototype, which has a unique song not heard in any leaked prototype or the final release.
  • Getting 2nd, 3rd, or 4th place has a different theme compared to final. In the final, this theme is used when you got no record in Time Trial mode.
  • Going over a bump with a Mushroom causes no sound. In the final, it causes a higher-pitched bump sound.
  • Using Lightning plays no sound.
  • Getting stomped by a Thwomp plays a different sound. Oddly enough, the earlier April 13 build used the final version of the sound.
Proto Final

  • Going the wrong way plays a slightly different Lakitu sound.
  • Hitting an enemy with an item plays a slightly lower-pitched sound
  • The sound effects of driving on terrain tiles such as the Donut Plain's grass or Bowser's Castle tiles are different or missing.
  • Going over the bridge in Donut Plains plays a slightly different sound
  • On the final lap when you are 5th or below a different sound plays, which is different than the one Lakitu plays when going backwards.
  • Using a ghost gives a 'proceed menu' sound when you steal an item and a 'go back to previous menu' sound when stealing no item. Likely placeholder sounds.
  • Finishing does not give the finished sound. Instead, the victory jingle (or defeat) will immediately start playing, proceeded with the character's victory theme.

Track Differences

Mario Circuit

Mario Circuit 1

2 item panels were added for the final release.

Proto Final
SMKMayAugustProto MC1.png SMKFinal MC1.png

Mario Circuit 2

Coins, item panels, a jump bar and zippers were added.

Proto Final
SMKMayAugustProto MC2.png SMKFinal MC2.png

Mario Circuit 3

More coins and item panels were added. The item panel before the finish line was replaced by a zipper.

Proto Final
SMKMayAugustProto MC3.png SMKFinal MC3.png

Mario Circuit 4

Coins were moved and added. The wall next to the item panel was made thicker.

Proto Final
SMKMayAugustProto MC4.png SMKFinal MC4.png

Donut Plains

Donut Plains 1

? blocks are in a different position, there are less coins than the final version and the walls don't have diagonal segments. This revision of the track can be seen in a screenshot from the game's international packaging.

Proto Final
SMKMayAugustProto DP1.png SMKFinal DP1.png

SMK DP1 Later Proto.jpg

Donut Plains 2

There are no coins before and after the finish line. It also features a ramp near the lake that was removed in the final version.

Proto Final
SMKMayAugustProto DP2.png SMKFinal DP2.png

Donut Plains 3

There are less coins scattered through the track. A very subtle difference is that the curve with two x-shaped coin formations on it is wider in the final version.

Proto Final
SMKMayAugustProto DP3.png SMKFinal DP3.png

Bowser Castle

Bowser Castle 1

Apart from the crown-shaped coin formation, no other coins can be found on the track. This time there are less zippers and, apart from having the ? blocks positioned differently, a ramp and a ? block can be found near them.

Proto Final
SMKMayAugustProto BC1.png SMKFinal BC1.png

Bowser Castle 2

The zipper is placed differently and there are two ? blocks surrounded by ramps that were removed in the final version.

Proto Final
SMKMayAugustProto BC2.png SMKFinal BC2.png

Bowser Castle 3

Notably, a path is blocked in Grand Prix and Match Race by an object left unused in the final game.

Proto Final
SMKMayAugustProto BC3.png SMKFinal BC3.png

Choco Island

Choco Island 1

Apart from having less coins and ? blocks, in the center of the track the multicolored wall is partially shifted to the right.

Proto Final
SMKMayAugustProto CI1.png SMKFinal CI1.png

Choco Island 2

The big mud puddle is split into bigger sections than the ones from the April 13, 1992 build and the area between them is filled with coins.

Proto Final
SMKMayAugustProto CI2.png SMKFinal CI2.png

Ghost Valley

Ghost Valley 1

? blocks have a completely different position and many tiles on the edge of the track are missing.

Proto Final
SMKMayAugustProto GV1.png SMKFinal GV1.png

Ghost Valley 2

The first group of ? blocks is split in two unlike the final version and, again, many tiles on the edge of the track are missing.

Proto Final
SMKMayAugustProto GV2.png SMKFinal GV2.png

Ghost Valley 3

There are less coins and the ? blocks are positioned differently. The shortcut is absent even in this build.

Proto Final
SMKMayAugustProto GV3.png SMKFinal GV3.png

Koopa Beach

Koopa Beach 1

The zipper was removed in this build and most of the objects are in their definitive position. A ? block on the small island hasn't been added yet.

Proto Final
SMKMayAugustProto KB1.png SMKFinal KB1.png

Koopa Beach 2

? blocks are positioned differently, but the available coins are in their definitive position.

Proto Final
SMKMayAugustProto KB2.png SMKFinal KB2.png

Vanilla Lake

Vanilla Lake 1

Some walls from the April 13, 1992 build were removed and it still contain a ramp that was removed in the final version. ? blocks are grouped together like the final version, but their position is slightly different and there are less coins.

Proto Final
SMKMayAugustProto VL1.png SMKFinal VL1.png

Vanilla Lake 2

Coins in the bottom-left part of the track are in their final position, but the rest of the objects are in a different position. Many ice blocks were removed in the final version.

Proto Final
SMKMayAugustProto VL2.png SMKFinal VL2.png

Rainbow Road

Rainbow Road does not yet have any Thwomps, and the track is narrower in most sections. Interestingly, there are more ramps than the final version.

Proto Final
SMKMayAugustProto RR.png SMKFinal RR.png

Battle Mode

The Battle Mode track order is different.

Course Name (Prototype) Name (Final)
Donut Plains N/A Battle Course 1
Koopa Beach Battle Course 4 Battle Course 2
Choco Island Battle Course 3 N/A
Vanilla Lake Battle Course 2 Battle Course 3
Mario Circuit Battle Course 1 Battle Course 4

Award Ceremony

Like the earlier April Proto there are several unique endings for ranking in the top 3 with two of them getting removed in the final.

Some changes were made. The unique 2nd and 3rd place ending cutscenes have been swapped around and have small changes in the animation.

1st 2nd 3rd
SMKmayproto Award1st.gif
SMKmayproto Award2nd.gif
SMKmayproto Award3rd.gif
  • In the 2nd place ending, the Super Koopa now spins after getting hit by the cork.
  • In the 3rd place ending, The fourth Paratroopa bounces it's way out after getting hit by the cork.

Other Notable Differences

  • The text formatting differs slightly. "GOLD.", "SILVER.", and "BRONZE." is on the same line as "GREAT RACE!". In the final, They are on the same line as "X WINS THE".

Debug Mode

Debug Mode has been enabled by default and has numerous input commands and features, as well as a possible course editor. Due to Debug Mode been made for the Japanese version of the game, some menu options on the main menu got corrupt Japanese characters, because the Japanese tileset been removed from this build. Furthermore, upon activating the main debug menu (Start + Select) starting any course completely crashes the game due to unknown reasons. The earlier April 13 build has much more title screen commands compared to this build.

Title Screen Debug Commands

  • Start + Select: Enter main debug mode
  • Select + B: Start a 50cc mushroom cup race (crashes if debug has been previously activated)
  • Start + Select + B + Y: Soft Reset back to the title screen (can be used everywhere)
  • L + A: Changes the first unknown value on the title screen with Debug Mode Activated. Goes until E. For some reason increase by 2 values each press
  • L + X: Changes the second value on the title screen with Debug Mode Activated. Goes until 3, and seems to be the World (cup) value.
  • L + Y: Changes the third unknown value on the title screen with Debug Mode Activated. Goes until 8

Debug screen.png
Super Mario Kart Debugging Menu
Description of the Debug Menu in Super Mario Kart's Prototypes