Before Capcom created Resident Evil Gaiden for Game Boy Color, they were working on a port of the original Resident Evil with HotGen. The game was reported to be near complete, but Capcom canned the project citing quality concerns. Resident Evil for GBC never saw the light of day aside from a few gameplay videos.
We *might* be able to play it, though.
A collector has two prototype carts that let players shoot zombie sprites with a shotgun and see some of the game’s event scenes. Both will be released on the Internet if the collector receives a $2000 bounty.
Details about the fundraiser are here, which has over $500 $1,498.63 in the pool so far and hundreds of dollars of promised donations. $2000 is a chunk of change, but many prototype games, even those now readily available, are dumped for a price.