Five levels, some ported from M2 suicides, some brand new. All quite playable (except maybe Kevorkian's Rooms, which will give you a horrible headache). Deadly Ledges is very nice for extremely high-carnage games.
A nice little four-room level... sort of a space station, only with daytime landscape textures. Teleporters decrease the linearity brought on by the geometry.
A very large, up-and-down level (the name is apt), with a small central killing space. Teleporters will dump you into nice little sniper nooks... one secret, explained by the single term.
An M2 level, updated with SMGs and a hidden term. For those who haven't seen it, movement is controlled by sewage-you can change direction, but forward motion is out of your hands. Takes some getting used to, but it plays pretty well.