I find it just fine. And so far I like it. Just a few things.
1: I'm thinking that the pit should either be extruded to infinity, or the floor should be black (like a void of eternity).
2: Some electronic sounds/voices wouldn't be bad, like the footsteps, announcers, etc. At least, I think the footsteps can be changed in some way without it being a mod (aside from ParseArg). Or maybe I'm mixing it up with an SP level of some kind...