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Proto:Super Mario Kart/mkart

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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:
  • More graphics and sound differences
  • More screenshots
  • Post a patch to fix the lack of hazards on certain courses in Grand Prix mode.
  • Check for more unused content
  • Duplicates of certain track tiles can be found, that were overwritten in later builds. Also check if these are unused.
  • Checkpoint zone oddities are present. Ex. Bowser's Castle 3 has an leftover extrusion for a STOP seen before the three paths in the Oct 1991 map.

mkart is a Super Mario Kart prototype dated April 13, 1992. The ROM was discovered in the July 25th, 2020 gigaleak.

To get the ROM working, change FF FF FF FF FF to 30 05 09 01 00 at 0x7FD5 to correct the header. To get Vanilla Lake 1 working, apply this patch.


SMKAprilProto DP1.png
Early Tracks
Pretty much every track was different. Including a scrapped Choco Island 3!
Early Audio
Some early and new melodies are here, including a different hip rave theme for Donkey Kong Jr.!

General Differences

  • The small demos shown after the title screen are absent in this build.
  • The ability to navigate the menus with Select has not been implemented yet.
  • The 150cc class is not present at all.
  • The Staff Roll is absent.
  • The Special Cup is unlocked from the start.
  • All trophies for 50cc and 100cc are obtained from the start.
  • The rival order is always the same: Mario, Luigi, Bowser, Donkey Kong Jr., Peach, Yoshi, Toad, Koopa. However, they have the same speed, so it can be changed.
  • The secret screen swap trick doesn't requires any button combo yet and can be simply done by selecting a 1 Player Game with Controller 2.

Mkart ScreenSwap.png

In Race

  • Coins, Boos, and Lightning don't appear in the item roulette.
  • The Bullet Bill (the moving ball enemy from Match Race) appears as a green shell an their locations on some of the tracks are different.
  • The player starts out with 5 lives instead of 3. It's impossible to have 5 lives in the final game.
  • No extra lives are given out.
  • The player doesn't start with any coins.
  • You don't lose coins when bumping into another racer.
  •  ? panels don't reset after all are passed through.
  • Computer opponents don't use character specific items yet. They only lay bananas and don't throw them in front of you yet either.
  • Most tracks seem to have their zone speed values set at a higher number, resulting in more aggressive AI. This is most prevalent in 100cc.
  • Opponents don't move out of the way of the player when in close proximity.
  • The player always starts the next race in 8th place (7th for player 2), regardless of what place they came in during the previous race.
  • Monty Moles don't attach to you like in the final. They will spin you out instead.
  • Cheep-Cheeps and Piranha Plants cause you to lose coins when you touch them, unlike the final.
  • The animation for getting crushed by a Thwomp is longer.
  • Cheep-Cheeps have an unique behavior when shot by Koopa shells. They will stand still shortly and cause the shell to bounce off with much lower speed.
  • Getting hit by an item such as a Green Shell or Banana has a shorter animation for spinning out, as it lacks the overshoot at the end of the "spin-out" portion of the animation.
  • There is no "Retry" and "End" options when losing a race. It will show the times for each lap and advance into the ranking screen, and restart the race afterwards. There is also no red "失格!" (Disqualified!) tagline that bounces down. The "Retry" and "End" options do appear if you pause and select "Yes" however.


  • Almost all of the text is different.
  • The timer appears in Battle Mode.

Mkart BattleTimer.png

  • The timer doesn't stops at 09'59"99.
  • After finishing a Battle or Match Race, the character doesn't turn their head during their losing animation.
  • Some of Lakitu's animations are either different or missing. His entrance when completing a lap is longer and he doesn't sway back and forth in one place when you go the wrong way. If you quickly turn back the right way, he will simply disappear rather than exit out. He also has a slower animation for pulling the player out of the lava.
  • Position numbers don't enlarge briefly when swapping positions and have slightly less contrast.
  • It is possible to skip the win sequence by pressing start after finishing a race.
  • The racer sprite doesn't jitter when it's moving.
  • The drivers who don't have at least 1 point spin out in the tally screen.
  • Racers who didn't make it to the finish line in time are labeled as "Out" in the ranking screen.
  • The "ゲームオーバー" (Game Over) text doesn't bounce down when giving up a Grand Prix race with zero lives; it just simply appears with no effect. Losing a race with zero lives will make the text bouncing down like in the final however.
  • When failing to beat a best time in Time Trials, the camera doesn't stop at the finish line when the player crosses it like when placing 2nd-4th, instead it still plays the 1st place/New record camera animation, where it turns in front of the racer.
  • In Battle Mode and Match Race, giving up doesn't give a win to the opposing player. Instead, the screen darkens and brings up a set of options, much like in Time Trials.
  • When a race starts in GP, there is no text that displays the round number.
  • There is no black border at the bottom of the map/player 2's screen.


Proto Mkart EarlyDrift.gif
Final SuperMarioKart FinalDrift.gif
  • The rocket start and burnout is absent.
  • Hopping is not possible.
  • Slight drifts (Hopping and holding Left/Right) are not possible.
  • Sharp drifts (holding L/R while drifting) are slightly buggy and can cause inconsistent rates of acceleration and can even slow you down.
  • Automatic drifting isn't implemented yet
  • To end a drift, you need to steer against the drift direction, otherwise you get another slow down. In the final version, ending a drift is done by a jump.
  • No matter how long the drift takes you get a mini turbo, while in the final version you have to drift for a certain amount of time to get the turbo.
    • The mini turbo is also quite long in the proto, and lasts almost 4 seconds, while in the final version it is about half a second.
  • Bananas can't be thrown forward.
  • Green shells can't be dropped.
  • It's possible to get the Star in 1st place. Unlike the final.
  • It's possible to use items while being in the flattened animation, something that can cause bugs.
  • Driving out of the water gives you a big jump with a small boost.

SMK mkart WaterJump.gif

  • Going into obstacles such as Pipes, Thwomps, Piranha Plants, Monty Moles, and Cheep-Cheeps with a star makes you feather jump, instead of knocking the pipe over.

SMK mkart PipeFeatherJump.gif

  • Bananas act like shells when colliding with them, putting the player to a full stop.



  • Attempting to load Vanilla Lake 1 normally crashes the game due to a problem with the track's checkpoint data.
  • If the player hits something that will cause them to spin out, and pause to restart or exit to another course in the duration of the camera spin, it's possible to race around with a different camera angle. The camera resets when the player hits something again.
  • After the timer reaches 99'59"99, the timer loops back.
  • Lakitu doesn't turn you in the right direction sometimes.
  • After a few minutes, the player moves a little bit to the upper right, which could cause you to clip through walls.
  • The secret screen swap trick in Grand Prix glitches the game when using other drivers than Mario, resulting into the player being invisible and able to drive though walls. The racers on the map screen will flicker and jitter. You start a lap behind and are locked at 8th place, making it impossible to finish at any other position. The game crashes at the ranking screen, and same goes for quitting the race.
  • It's extremely difficult to rank in the top 4 in Vanilla Lake 2, due to the aggressive AI, broken item distribution, and the inability to jump over gaps. The reason for the fast AI might be that the individual speeds for their target points weren't set yet and were set to the default value, which is the fastest one.

Physic Related Bugs

  • Colliding with a wall while underwater or driving into the water with a star active causes you to regain acceleration as if you were on the track.
  • CPU opponents who are rescued by Lakitu can sometimes levitate in the air for the remainder of the race.
CPU Luigi hovering, an occasional result of Lakitu rescuing an opponent.
  • If you feather jump out of bounds or fall off the track, both with a star active, makes it possible to "drive" when Lakitu is rescuing you, giving you control to drive anywhere, especially when picked up outside the track, though you may go faster or slower depending on the direction you are facing
  • Red shells thrown at CPU opponents often go through them without hitting them. This usually happens when you are too close.
  • When driving behind a CPU opponent while it lays down a banana, the collision doesn't register in time and the banana will go through the player.
  • The edges from the bumps on Choco Island aren't programmed properly and can throw the player sideways.
  • If you hit a wall while falling off or in the lava, you can drive while Lakitu is grabbing you, which can cause a lot of glitchy results.
  • Drifting in circles in off-road sections will cause the player to spin out indefinitely until they release the gas or exit exit the off-road.
  • If you release the gas while performing a sharp drift, the drift will continue while you're still in place until you spin out.
  • Player 2 doesn't spin out from touching the Cheep-Cheeps in Koopa Beach.
  • If you hit a Monty Mole while underwater, the spin out animation is stored and won't play until you exit the water.

Audio Related Bugs

  • The engine sounds from the computer opponents can still be heard after a race. Same goes for when colliding with a wall

Visual Related Bugs

  • The animations for the water splashing continue to play even when the player remains idle.
  • Lakitu sometimes appears on the bottom map screen, usually when the computer nears or falls into a body of water or lava.

SMK Mkart LakituMapScreen.png

    • Going into rear view mode in this moment causes Lakitu to glitch all over the screen
  • In Battle Mode, the characters will constantly turn their head.
  • If you feather jump into the lava when finishing the race, the animation for being rescued will be glitched.
  • Toad's tire flashing palette can continue to flash on the map screen even when he remains idle. This is done by reaching full speed and slowing down afterwards.

AI/Checkpoint Related Bugs

  • The checkpoint data for Vanilla Lake 1 appears to be unfinished (or overwritten by accident which could be the cause of the crash) and the AI can't complete the race. The AI struggles to get past a striped wall (Though they may break past if the hit an item laid in the same spot), then they continue to the lower left section of the map at the final turn where the checkpoint data abruptly ends, causing them circle that spot indefinitely, since the last few zones are missing.

SMK mkart VL1 AIGlitch.png

  • The AI struggles to get over the bridge in Donut Plains 2 and 3 for the most part.
  • The AI appears to swerve around a bit in certain parts due to the messy target placements or very tight turns with high speed values.
An example of swerving AI in Donut Plains 2, with Peach, Luigi and D.K. Jr. cutting off-road and Bowser going too fast on the last turn.
  • In Bowser's Castle 1, the AI crashes into the wall on the bottom left from going too fast from the zippers.
  • In Bowser's Castle 2, The AI occasionally messes up at the split section at the bottom and fall into the lava.
  • In Bowser's Castle 3, AI opponents who take the path with the zipper will go too fast and drive into the removed STOP located at the final bend, They tend to lag far behind as a result.
  • In Mario Circuit 2, if a computer player fails to make the jump towards the end, they will indefinitely ram into the wall and not turn right to retry the jump.
  • Mario Circuit 3's checkpoint data is completely broken, and the CPUs indefinitely ram into the walls beside the checkered line. Most of the targets seem to be pointing in the wrong direction and Lakitu will think the player is going the wrong way in some areas.

SMK Mkart MC3 AIGlitch.png

  • In Koopa Beach 1, the AI drives into a deep water pit on the right and sinks. It's possible that it wasn't there in earlier versions and the AI data just hasn't been updated for the AI move around it yet.
  • In Koopa Beach 2, the AI rams into the wall in the upper left corner of the map and into the deep water next to the shallow water section. This is due to the track's checkpoint data being reminiscent of an earlier version of the track presumably predating this build.
  • In Donut Plains 3, the AI sometimes don't take the right curve at the down right corner of the map and instead drive to the left into the grass, then trying to drive back. This is possible due to a misplaced AI target point. It's also possible for the AI to get stuck out of bounds if the reach far enough to the right wall.
An example of the AI struggling in Donut Plains 3, with Yoshi stuck out of bounds, and D.K. Jr. and toad in the water, a result of the misplaced target point.
  • In Choco Island 3, due to the sharp turns, the AI has a hard time staying on the road and will occasionally get stuck at a wall on the right.
  • Some tracks have their finish line data length set to short, which makes it possible to skip tracks by driving along the wall next to the finish line. The tracks were this is possible, are:
    • Choco Island 1
    • Donut Plains 2
    • Koopa Beach 2

Track List

The tracks are in a different order than the final game and the later prototypes, and some have different layouts. Notably, this build lacks Rainbow Road, instead having a third Choco Island course.

Proto Final
Mushroom Cup
Donut Plains 1 Mario Circuit 1
Choco Island 1 Donut Plains 1
Ghost Valley 1 Ghost Valley 1
Bowser Castle 1 Bowser Castle 1
Mario Circuit 1 Mario Circuit 2
Flower Cup
Koopa Beach 1 Choco Island 1
Choco Island 2 Ghost Valley 2
Donut Plains 2 Donut Plains 2
Bowser Castle 2 Bowser Castle 2
Mario Circuit 2 Mario Circuit 3
Star Cup
Ghost Valley 2 Koopa Beach 1
Vanilla Lake 1 Choco Island 2
Donut Plains 3 Vanilla Lake 1
Bowser Castle 3 Bowser Castle 3
Mario Circuit 3 Mario Circuit 4
Special Cup
Vanilla Lake 2 Donut Plains 3
Koopa Beach 2 Koopa Beach 2
Choco Island 3 Ghost Valley 3
Ghost Valley 3 Vanilla Lake 2
Mario Circuit 4 Rainbow Road

Graphical Differences

To do:
There's more!


Proto SMK Mario Proto.png SMK Luigi-Proto.png SMK Bowser Proto.png SMK Yoshi Proto.png SMK Koopa Final.png
Final SMK Mario Final.png SMK Luigi-Final.png SMK Bowser Final.png SMK Yoshi Final.png SMK Koopa Proto.png

Several character sprites received minor tweaks.

  • Mario and Luigi eyes always looked straight forward and have an outline on the back of their kart.
  • Koopa Troopa didn't have squinting eyes from some perspectives.
  • Bowser's jaw is slightly sticking out and the shading on his leg was slightly altered.
  • Yoshi appears more closer to the final international version.

Also, Luigi uses his own body graphics, whereas in the final, he uses Mario's body graphics as a way to save memory. His seat is also blue and his shading looks partially unfinished.

Proto SMK PeachIcon Proto.png SMK DKJRRank Proto.png
Final SMK PeachIcon Final.png SMK DKJRIcon Final.png

Peach and Donkey Kong Jr.'s ranking icons were redrawn. With Peach having a narrower face than the final.

Proto Final
SMK DKJR Podium Proto.gif
SMK DKJR Podium Final.gif

Donkey Kong Jr. is missing the letter on his shirt during the Award Ceremony and the shading and pixel placement was slightly tweaked.

Item Slot

Proto SMK Proto 1P.png SMK Proto 2P.png
Final SMK Final 1.png SMK Final 2.png

Before getting the first item, The item slot will display the player number. In the proto there is a "P" for player added next to the number.

Lakitu Flags

Proto Final
SMK prerelease EarlyReverseFlag.gif
SMK prerelease FinalReverseFlag.gif

The yellow reverse flag was missing the X and some pixels were moved.

Proto Final
SMK prerelease EarlyCheckeredFlag.png
SMK prerelease FinalCheckeredFlag.png

The edge of the flag was changed slightly.

Cheep Cheep

Proto SMK CheepCheep Proto.png
Final SMK CheepCheep Final.png

Cheep Cheeps flop upside down in the proto.

Screen & Menu Layout Differences

Title Screen

Proto Final (Japan)
SMK Proto Title.png Smk title screen jp.png

Mario’s mouth is closed on the prototype title screen. Aside from that, it's pretty much identical to the final Japanese version.

Select Screen

Driver Selection

Proto Final
SMK CharSelect Proto.png SMK CharSelect Final.png

Everyone except Mario, Yoshi, and Toad was rearranged.

Cup Selection

Proto Final
SMK CupSelect Proto.png SMK CupSelect Final.png

An orange border and a heading with the selected cc class was later added to the Cup selection. All trophies are obtained from the start.

Course Selection

Proto Final
SMK mkart TTCourseSelect.png SMK Final CourseSelect.png
  • The text for inactive choices is white instead of red.
  • There is no spacing between the course name and the number.
  • The text placement is shifted slightly.

Results Screen


Proto Final
Mkart ResultsScreen.png SMK FinalResultsScreen.png
  • Slightly different layout.
  • The Cup's icon is absent.
  • The cc class isn't shown.
  • The player's selected driver doesn't blink.
  • All of the text inside the border is outlined in white. In the final, only the top 4 racers are outlined in white.
  • Some racers have sometimes corrupted tiles on them.
  • Computer opponents who didn't make it to the finish line in time are labeled as "リタイア" (Retire) in the ranking screen. In the final, they are given a time regardless. This functionality is still used in the final when one of the players in 2 player GP gives up the race and/or loses all of their lives.
  • After the player loses a race, and this screen appears, it will display the previous round number instead of the current round. If you lose on the first race, it will say "ラウンド 0" (Round 0) Instead of "ラウンド 1" Round 1.


Proto Final
Mkart StandingsScreen.png SMK Final StandingsScreen.png
  • There was no animation of the point counter.
  • Much like the results screen, it's missing the cup icon and cc class.
  • The racers who don't have at least 1 point spin out, while in the final, the drivers who didn't make it into the first four places spin here.
  • Sometimes, one or more racers are slightly turned in the wrong direction.

Award Ceremony

The proto has several unique endings for ranking in the top 3. Two of which are not seen in retail. The fourth place ending is also absent in this build. The player is taken back to the cup select screen afterwards, unlike the final, where the player is taken back to the title screen.

1st 2nd 3rd
MkartProto Award1st.gif
MkartProto Award2nd.gif
MkartProto Award3rd.gif
  • When finishing 1st, a giant inflatable Cheep Cheep hovers above the podium, except this time, it doesn't spit out a trophy and has a slightly different path when shot out by the champagne bottle's cork.
  • When finishing 2nd, four Koopa Paratroopas fly above the podium, with the fourth one walking away after being shot down by the cork.
  • When finishing 3rd, a Super Koopa enters the scene and makes a loop above the podium, which then gets shot by the cork on its way out.

Other Notable Differences

  • The background uses the generic oval clouds seen in Mario Circuit, whereas in the final, the clouds change depending on the cup. The sky is also yellow instead of blue.
  • The "おめでとう" (Congratulations) tagline is different and has no animated color palette. It also doesn't bounce once it's zoomed in all the way.
  • There is no proper text for congratulating the player on their victory, so it will display a bunch of 1s instead. Most likely a placeholder.
  • The special award song doesn't exist yet so the early titlescreen theme is used here.
  • Donkey Kong Jr. is missing the letter on his tanktop.
  • The characters in 2nd place and 3rd place cheer throughout the whole cutscene in the build. In the final, They cheer once the trophy lands on the road.
  • No confetti falls from the sky.
  • No sound effects.
  • The podium itself is placed lower on the screen.

Some of the characters' animations with the bottle differ from the final

  • Mario doesn't cheer with the bottle when the water shoots out.
  • Toad cheers with the bottle and water shoots out. In the final, he doesn't cheer with the bottle and a vine grows out of it instead. This animation was later reused for Mario's cheer pose.
  • Like the final Japanese version, Peach and Bowser drink from the bottle, which is ultimately cut from the international release to comply with NOA's policies.
  • Yoshi tosses the bottle from hand to hand with a much lower trajectory than the final.

Debug Features

Soft Reset

Start + Select + B + Y: Soft Reset back to the title screen (can be used everywhere).

Title Screen

At the title screen, some debug features can be used by pressing a certain combination of buttons. These features are very buggy and read the menu choices (class, mode, driver, and track) that were selected before, so it is sometimes required (depending what debug feature you want to access) to select some choices on the titlescreen before, otherwise the game may crash or give different results when using them. (To make it easier, select your choices on the titlescreen up to the driver select and then hold Y+B+Start+Select to go back to the titlescreen to access the debug feature.)

Press Select and one of the following buttons on the title screen to access a debug feature:

Select + R

Loads a track selection screen. It uses a variant of the Time Trial one and Mario is set by default as the character for the player. If the player didn't access the driver select menu in Time Trial before (using the main menu), the selected track crashes as soon Lakitu's countdown finishes or when one of the players starts to accelerate (it may glitch and allow another player to participate).

If Battle Mode was accessed before, the game will send you to the battle arena selection instead.

Final choice before starting the race
Track Select Time Trials
SMK mkart Prototype Track Select Choice.png SMK mkart Prototype Time Trials Choice.png

Select + Y

Starts a Match Race with the last selected drivers and track, if Match Race was selected before. If Battle Mode was played before, it will start a battle.

By default it will start a glitched 2P Grand Prix on Mario Circuit 3 that makes the game crash when it finishes, with Mario (Player 1) and Luigi for (Player 2) and no computer players. The players have 0 lives and screen is almost blackened because the game is put in a "game over" state, but the players can move and they are visible on opposite screens (Mario appears on Luigi's screen and vice versa). Quitting the race triggers a Game Over.


Any other mode that was selected before will crash the game or start a 1-Player solo race that crashes the game as soon the start countdown finishes.

Select + A

Crashes the game. According to kart-init.asm from the source, this is supposed to open up EDIT1, which is the checkpoint data editor.

Select + B

Starts a Grand Prix with the last selected driver and cup. The Mushroom Cup with Mario set as Player 1 will load by default.

If Battle Mode was played before, it will start with a glitched battle on the first track of the last selected Cup. The players appear to have no balloons, their speed is faster than normal, and laps don't work. When the battle is completed and you go to the driver or track selection, everything will be set back to normal Battle Mode.

If a Grand Prix in 2-Player was played before, it will start a 2-Player Grand Prix instead of a 1-Player one.

If Match Race was the last choice, the game will crash.

Select + X

After the screen becomes black, the game softlocks or crashes. In the earlier uncompiled Feb proto, it will open up EDIT2, which is the object overlay editor.

Select + Start

Crashes as well. In later prototype builds it will load a Debug Menu.

Any other button combination won't do anything.

Unused Graphics


SMK prerelease EarlyCoin.png SMK prerelease EarlyCoin animated.gif SMK Prototype Coin Animation.gif

A coin sprite with graphics for different distances can be found among the item graphics. This could mean that the coins were originally supposed to be standing on the track rather than laying flat, an idea that would be revisited in Mario Kart 7 and 8.

It's also most likely a leftover from the scrapped Coin Runners mode and other modes found in the November 1991 prototype.

The coin graphic used for the coin collecting animation can be found among Lakitu's graphics.

Unused Font

Mkart UnusedFont.png

A full small font found among the Item Storage and the Race Time numbers, most likely used for debugging purposes and such. The first row can still be found in the final.