I haven't played it multiplayer, but I think this map will have a lot of action.
However, I know a little improvement to it: you should make more walls solid, so that oculling works better. To understand what I mean, enter edit mode and fly above sky, looking at your angled walls. Your angled walls are hollow, and cube thinks "you can see through" those walls.
I've filled all hollow walls, and my modified version can be found here: http://rapidshare.de/files/2581074/foundation2.cgz.html Feel free to use my modifications and incorporate it to your package.
My changes fixes two things:
- Oculling works better now (although the level does not have many ocullers).
- When possible, Cube Engine will use bigger cubes to draw walls. Before, Cube Engine was forced to use only small cubes, because walls had 1-cube width,