Doom on the 7Mhz, 16-colour, 1Mb Amiga 500 might sound unrealistic, but this is one of a handful of games that managed it, and the first full Doom-style game for the Amiga.
Unusually the multiplayer game was split-screen, which didn't really work because you could sneak a look into the other window to see where your opponent was - it's not exactly full of suspense.
The major compromises in getting the game onto the A500 are the graphics, which lack texture-mapping, and the trick-3D used where the characters don't rotate smoothly in 360 degrees, but jerk through a small range of viewpoints, a la Dungeon Master. Only half the screen is used for the actual motion as well, with the rest reserved for RPG-style artwork - which is obviously superfluous because the 2-player game doesn't have it. It's a throwback to the first Lotus game of all things. You can even turn the animation off.
In one-player mode there are 34 levels, accessed via passwords, 3 lives, and lots of powerup weapons. If one player completes the level, both advance to the next one (like Lotus 2, funnily enough. I guess I ought to think of a similarity to Lotus 3, just to complete the set). There's also the standard Death Match mode.