Following the success of the original PlayStation edition of Resident Evil in 1996, Capcom expanded the game in a number of ports - one of those planned was for the GameBoy Color. In 1999, HotGen Studios, Ltd., a company in the United Kingdom, was selected by Capcom to port the game.
HotGen designed the game to be a direct-conversion of the PlayStation version following the same single-player paths as other versions with options to play as either Chris Redfield or Jill Valentine. New additions were also planned including a greater variety in enemies and the ability to disarm traps. A new save feature was also in development, removing the need for Ink Ribbons and finding save points.
However, after sending the finished product to Capcom for evaluation, the company turned it away. Their official statement in 2000 claimed that they were "not confident that the product would have made both consumers and Capcom happy."
Since the game's cancellation, two cartridges containing the game's ROM dumps have been recovered. The second one found, "Cartridge 2", is an older version of the game.
"Cartridge 2" is considerably more buggy than the later "Cartridge 1". The codenames which appear onscreen are based upon the order they were purchased by the ROM dumper. Only Chris is playable in this build and the game is very incomplete for the most part compared to the "Cartridge 1" build.
Both versions end at the Lab Elevator, although elements from the final areas remain unfinished
The "Bazooka". According the description it kills enemies in one hit. However, it doesn't seem to be possible to equip it. The coding probably wasn't complete at this point.
Barry giving Jill Forest's "Bazooka".
Jill fighting a Zombie with a Shotgun in the Storage room stairway/Hallway.
Forest's dead Body in 8-bit.
Jill in the Storage Room under the stairs in the Spencer Mansion. Yes, that is a debug mode of sorts showing the player's current location.
A Zombie in a Hallway. The Zombies don't lay on the ground when they die. Instead, They fall on their knees and stay that way.
Chris and Barry seem to use the same sprites in the game. Though Barry appears to have been edited to feature his trademark beard.
If the player waits on the title screen for a bit, the game will cycle through various backgrounds found throughout the game. This is one of the images of the outdoors portion of the mansion involving the bridge that accesses the waterway and needs a crank to work.
Another background the game's "demo mode" cycles through.
Yet another background that the "demo mode" cycles through.|Another one of the various backgrounds the game cycles through.
Barry seems to be a slightly edited version of Chris's sprites in this game. The only addition seems to be the beard to differentiate his sprites from Chris's.
This is prototype build 2's intro. This build is much earlier than the one above as previously mentioned. This earlier version forces you to play as Chris regardless if Jill is selected or not. There are also more bugs than the other one.
Unlike the later build above and the other ports' final versions, Chris starts off with his Beretta, Shotgun, and Survival Knife in his inventory. In the later build, he starts off with only a Survival Knife, Just like in all the other versions of RE1.
This is actually in both builds but since it wasn't shown above, it will be shown here. The Zombie that killed Kenneth noticing Chris/Jill. The color pallete shows certain limitations resulting in many odd colors.
This odd overlapping bug with the Zombie that killed Kenneth is fixed in the build above. This earlier build is considerably more buggy than the other since it is earlier in this port's production.
As was mentioned earlier the Zombies don't fall on the ground when dead. Instead, they fall onto their knees and stay there. This is present in both builds. It's possible that the animations for the Zombies' deaths were simply not finished yet.
It has been said recently that the full ROM for this game is available by one of the games developers. However the gentleman will sell the one of the two ROMs (one was given to Capcom) for US$2000. The website Assembler games has attained all the money. However, the community was given both ROMs, not just the first build.