About those transparent surfaces, I would not turn them into glass. IMHO this map works with stuff that's not shiny and not very bright (the lights present now are perfect). Glass will only break that if used. I suggest drawing some lines or something to mark those surfaces, using the same stuff as for the circles under the items (see screenshot).
Another thing that would make it nicer IMHO would be adding some sort of pipe-looking thing that would carry data (since it's a CPU) across the arena, with something like moderately bright flashes of light travelling trough that thing... This might add more life to the map.

I'm looking forward to playing it online
