A standard small arena, except for the Yeti room... they don't seem to attack, as long as you stay on the ledge. Also contains some pretty disorienting elevators (ever see a river jump?).
A nice conversion of a Mike Neylon M1 map. Lighter than the original, I think... has an added water pit below the stairs, but I've found it's pretty hard to hit, at least from the top.
A pretty straightforward port of the M1 Bungie net level. It would have been nicer if the fighters had been mapped back to fighters, instead of left as ticks... they're pretty annoying.