A sprawling, symmetrical, multilevel map which is extremely easy to get lost in (since it looks the same in many places). Dark, and big, and hard to figure out if your fodder is above or below you... this one is good for lurkers.

A wheel-like map with seven spokes. A bit of 5D space gives you a pair of upstairs...personally, I prefer the one with the recharger.Hard to tell, but v1.1 seems to have more monsters than 1.0 had. (No mention in the readme what the changes are.)

A very nice large arena, with a fast-moving peripheral ring. Two rechargers in the center, but if your opponents are any good, you won't be able to use them. In solo mode, the aliens give you a nice run for your money... troopers and hunters regenerate at absurd rates, but enforcers and fighters are on your side to help out. (Careful, though... there are enough enforcers that friendly fire is a real hazard.) Attractive design, and great flow.

Two maps (well, there are three, but the first and the third are identical) with some very interesting physics experiments. The first map has a very useful jetpack built into the second trigger of every weapon. One of the best I've used. The second has some pretty serious weapons modifications... as a solo test level, this one'll keep you coming back for more, and as a net level... well, carnage rates will be pretty absurd. Nicely done, as experiments go. Give 'em a try!