or just get windows :P!
but ok, back to the map...
ill keep it pretty simple,
the texturing should be rechecked, just because the low ammount of textures and there are textures that arent fitting their geometry (like the tile texture on the bridge).
the lighting should be changed. its just plain white, wich makes the map boring. after i saw how many lights you added in the map, it looks like you just spammed light everywhere without any purpose. like 90% of all light entinities dont have any lightsource at all.
the geometry isnt that nice. i dont mind square maps, but i dislike random square maps.
the detailing isnt much either.
the flow isnt bad, but thats just because its open design.
the gameplay isnt pretty good. almost no places to cover in the map (especially at the highest and biggest platform, there you only got a bridge that could cover you).
pickups arent great either, because no health and/or armour has been added. make sure there are at least some health in it.
clipping noclipping isnt that great too. the map looks like a typical cube 1 arena map, with a tiny cube engine 2 touch. you can easily go outside the map, wich shouldnt be, just because of the arena theme.
the map is just symmetric, wich is pretty bad for a deathmatch map. try to make maps (especially deathmatch maps) unsymmetric to keep it more natural.
anyways, not a great map. lots of things could be done better. ill give 3/10 for it.