Nice. It has been a long time since I last saw a nali-styled map among all these industrial ones. Refreshing.
Here are the things I've found:
1st: The first arena has a lot of long tight corridors, I'd change those a bit. (More architecture + make it wider) One of the crates has a BSP hole...
2nd: Basically, there's nothing wrong with the second one...and it's the fastest of the 5 arenas IMO. The layout is a bit standard tho...but it's just my opinion. Oh, and that lava texture is a bit strange. Use a more realistic one...eg the one from NaliFX.
3rd: Add more exits (eg. an elevator) to the lower hall. If you fall down from the Krall room you can get trapped because all exits are on the other sides of the room.
4th: I liked the 4th arena, that has the best looks of the 5 maps. You should add some kind of closed exit (door or a pile of rocks...etc) to the ends of the canyon. The walkways are a bit narrow...
5th: The fifth arena is slow...that huge dynamic light is eating all the framerates. (Type stat global into the console and you'll see that the Illum. times are 40-50 milliseconds...this should be kept around 1-2 milliseconds
)
General: The windows aren't nali-style...and that huge rock wall around the level in the skybox looks weird.
That's it..
Tata!
