This one's pretty slick. A two-player game (more will crash Marathon). 5-D space taken about as far as it can go. Check it out!
A 5-D map. Nice and clean, with some nice sniper ledges...
Another strategy map. There's a room that controls doors and a crusher in another room. The control room is pretty vulnerable. The crusher room has all the goodies. Where will you go?
Teleporters send you to a small prison for 45 seconds, where your enemies can take potshots at you.