Proto:Super Mario Bros. 2

The prototype of Super Mario Bros. 2 was bought in cartridge form on eBay and afterwards dumped. It features some interesting changes done during the conversion from Doki Doki Panic to the final Super Mario Bros. 2.

General Differences

 * Some minor changes here and there.
 * Running is not yet implemented.
 * Eyeballs aren't white.
 * Hold positions are totally wrong.
 * Several objects are lacking animations.
 * The "idle" Phanto sprite is not implemented yet. All Phantos seen in key rooms are static background objects; the enemy sprite is not actually spawned until you leave the room. (The implementation of this sprite in the final version led to a somewhat amusing oversight: re-entering a key room while still holding the key will activate the idle sprite again, causing two Phantos to chase you.)
 * The cartridge contains an MMC1 mapper chip, 128KB of PRG ROM, and 8KB of both WRAM and CHR RAM. This configuration is fairly similar to that of the Famicom Disk System, and was used by a number of FDS-to-cartridge conversions. The final game's hardware was upgraded to an MMC3, 128KB of both PRG ROM and CHR ROM, and 8KB of WRAM; this allowed for greater variety in the graphics, animations for objects that were previously static, and the cartoon-like ending sequence. Load times between levels were also shortened, as graphics no longer had to be copied to VRAM.

Debugging Features
There are some debugging features enabled in the prototype to make testing easier:
 * You can select which world to start in by pressing A a certain amount of times on the title screen. If you don't press A it defaults to World 1 (obviously), but by pressing A a number of times corresponding to a certain world, you can start on any world you want. However, there's no limit on how often you can press the A button, leading to the ability to start on invalid worlds (much like the Minus World in Super Mario Bros.). These worlds will either crash the game, load 1-1 with corrupted graphics, or the graphics on the character select screen will get screwed up, sometimes to humorous effect. If it doesn't crash, the game will occasionally cause slowdown. You can't complete the level, because it fails to load the next section after you have gone through the door.


 * If you press Select during gameplay you get 15 HP. The life counter becomes a glitchy mess but it will still work. Note that if you collect a life heart in this state, the life counter will actually overflow. Interestingly, this debug feature was shown in a commercial for the game.
 * You can continue an infinite number of times.

Music


The underground theme is a remix of the one from Super Mario Bros. with loud drum samples, which in turn is similar to the one used in Super Mario Bros. 3. In the final, it was replaced with a spruced-up version of the Doki Doki Panic underground theme.



The invincibility theme uses noise-based drums (like SMB1), rather than the drum samples of the final.

Intro
The title screen uses a different, rather monotonous yellowish palette in the prototype which was changed to the final's red/blue palette. Also, the story has slightly different wording in the prototype, most notably that Mario heard a faint voice as opposed to just a voice.

Character Select
The Character Select screen has ellipses between "EXTRA LIFE" and the amount of lives, which were removed in the final for some reason. The prototype is also missing the inside edges of the curtains, though the graphics are present in the ROM. Finally, you start off with 19 lives, which is more than likely for testing purposes.

World Intro
The "WORLD X-X" text was positioned slightly differently in the prototype, and World 7 has no scenery shown at all.

Bonus Chance
The bonus screen is a completely bland green screen similar to that in Doki Doki Panic. The final uses the prototype's title screen palette with a black background (which itself got reused as the Super Mario USA title screen).

Mushroom Blocks
In the prototype, the Mushroom Blocks of World 5 are the same as those in World 1. The final added spots to the World 5 blocks to differentiate them.

World 7 Vegetable
The World 7 vegetable, held over from Doki Doki Panic, is tall and lean and was changed to a short, squat design for the final.

7-1
In the third part of 7-1, there was an additional cloud platform to the left of the tall pillar and ladder, guarded by a grey Snifit. It was possible to leap from the Snifit's head and pass over the top of the pillar, thus bypassing a significant portion of the area. This was somewhat fixed by removing the platform and moving the Snifit onto the short pillar to the left, though Luigi and the Princess can still take the shortcut.

7-2 Birdo Room
In the room in 7-2 where Birdo protects a key, there is no Phanto present, as the idle sprite had not been implemented yet.

Ending
When you release the Subcons from the jar, a Thank You message appears on the screen in the prototype (as it did in Doki Doki Panic). This message was removed in the final.

The Subcon release scene is glitchy if you're Luigi or Toad. If you're Luigi, he will jump inside the jar and pull out the plug. If you're Toad, he will jump across the screen multiple times, pull out the plug in mid-air, and then continue to fly across the screen.

Instead of a contribution score, you get prize money based on how often you died – the less you died, the more money you got. The table goes as follows:

The prize money tiles remain in the final, but go unused.

The game ends on a simple "THE END" screen. The Mario scene and remixed Doki Doki Panic intro music are totally absent.

Sprite Changes
Some changes were done to the sprites.

Eyes
Mario, Luigi, and Peach got some white eyeballs for the final.

Luigi
Small Luigi's front foot is less round in the final.

Toad
Small Toad's feet were seemingly removed in the final.

Peach
Peach's hair has been altered slightly to be less in her face in the final.

Peach's face was redone for the final. Her face was almost unrecognizable in-game.