Two maps, one for small groups and one for large. Neither is huge... At first glance, this is a very simple map, but some of the dead ends actually make nice ambush spots, and a few of the escape stairwells will catch your feet if you're running away and not paying attention...
First level of a 5-level scenario, Krylark the Fallen. Interesting plot, but the AI can't spell worth a damn. The level is almost too difficult to bother with... lots of tight corridors filled with purple compys and tanks (nowhere to dodge projectiles, or explosions). Nice construction, though... the transparent walls in front of lava might be overdone, but there are some nice tricks. Also comes with a copy of Carnage Island (looks like version 3, but I can't be sure).
Fast-paced, multilevel map. Ostensibly a circular arena, but most of the action occurs in narrow passageways or the small central room. Best with bigger groups. Update tweaks textures, makes it harder to take a lava bath. (Although there certainly are benefits!) V3 update: The central area is now outdoors. Readme lists other changes, but they don't really seem major in terms of gameplay...
Textures are painful at low res, but this map'll keep you moving (those nasty purple compilers just keep shooting...). Big weapons carry a penalty.