One of the funniest- No... Funniest first-person shooters of all time.
Well, the graphics are, well. Imagine MS-DOS Doom. It's like playing with colored paper pieces, but the game is still (over) 10 years old, so what would you expect? Still it doesn't ruin the fun from the game.
Sounds, well. The game is pretty old, so the sound effects were really great back then. Well the music is still good.
You actually don't get anything if you beat the game, but you can try playing it in harder difficulties.
The game is really fun, one of the best back then.