Did you know Resident Evil was developed for the Game Boy? After the success of Resident Evil (aka Bio Hazard) development began for a Game Boy Color version. I remember reading about this in GamePro magazine (a video game magazine similar to Xbox Magazine (affiliate link) except for all consoles) and thinking it was an impossible task. Resident Evil was a 3D game. The Game Boy was not a powerful platform, and could not handle 3D.
It turned out I was right and wrong about Resident Evil on the Game Boy Color. The game was cancelled, and was never released. But in February 2012, a copy of the prototype game found its way online, and it was near completion. So what happened? Well let me say that several things are missing from the game, such as certain enemies and weapons. There is also unlimited ammunition automatically for each gun, so there is no need to collect ammo. Some animations are faulty, and there is one repetitive sound track for the whole game.
Even with the faults mentioned, it is incredible that Resident Evil even exists on the Game Boy color. The original game, for the Sony Playstation and Sega Saturn, had per-rendered backgrounds. This meant that the rooms the characters were in while playing the game were actually a still image or picture, and only certain objects or things were actually being seen in 3D. With this in mind, Resident Evil did not contain many real-time 3D graphics anyway. The Game Boy Color version takes the same approach, by using a still image for each room, and then laying characters and objects on top. The only difference is that instead of the objects being in 3D, they are simple drawings, or sprites.
For comparison, here is a picture of the Resident Evil on the Saturn: