a nice first attempt
a few points from me:
the random shark made me laugh.. is there a reason for this?
the ground: you have used a 256 square terrain for the flooring in this arena, many big dm levels dont use terrain that size, thats a lot of polygons for the engine to compute; you'd be better of performance wise (and overall map size) using a brush for the floor.
the lighting of the crowd section is waay too washed out, i changed the ambient brightness (via your zoneinfo) from 255, to 35 and it gives a more realistic (and less eye straining) look.
again, to rant on about lighting, there is 1 light in this level, the rest is lit via zoneinfo or the sunlight actor, using only one source of light can lead to your map looking washed out..
although these may sound quite severe points, its a nice map and shows some potential, gj, ill look forward to the next one
