Tight, almost claustrophobic corridors, lots of teleporters, and bobs everywhere. Easy to kill a few by accident (and then your friends aren't the only ones out to get you...).

A multilevel arena. With aliens on, you're gonna be spending most of your time fighting ticks.

A large level, with architecture reminiscent of the author's Alhambra. A bit darker, though... and with more indoor space. The author has suggested a somewhat unique solo method of play-see the readme for an URL with details.

A dark arena with some sniping areas around it. A straight port of the M2 version.