Might be a nice way to get into WASM development, but 4 colors sounds very limiting. Ok, I know the original Game Boy made do with only 4 "colors" (but that was on a black and white display where you probably couldn't have told the difference if there would have been more "shades of gray"), and the Game Boy Color showed these games using a palette of 4 colors, but actually even that device could show 56 colors at the same time!