A simple arena in two flavors... one has a walkway around the outside of a lava pool, the other is the same with a hill poly in the center. Weapons are really tight (looks like they're set up for two-player games... which is okay, I guess, since more than three (or maybe four) would be insane.

A pretty interesting level, with lots of secret (or semisecret) doors. Flow is great, once you've figured out where these doors are... and there's a little something for everyone. Open spaces, tight corridors, hideaways... there's always a way out of wherever you are. Watch the double jugs (non-trivial to trigger, so you may not see them).

The focus recently has been on solo levels, but this is a pack of 26 consistently very good net levels. These guys like narrow raised walkways and sharp corners, but overall, flow is great, texture choices are very tasteful, and weapons are plentiful. There are some very cool tricks (I liked the stairways on Pseudo Bridge a lot), and nice lighting on several maps. No matter what size your group is, you should find maps you can die in here...The only downside is that they're actually asking for money if you like the maps. Update fixes a couple of small bugs

Take House of Pain, open up the outside walls, add crossed trenches in the center, and brighten up everything considerably, and you'll get this well-built large arena, equipped for up to 8 players comfortably. Nice roof...