Take a look at my new Map Design: Molten Core
This map is designed to be a little "hot" in the center, made for a volcanic environment, for a future update (Probably a long time from now)
Too bad hot zone is gettin' the "Rush Wars" treatment
You're getting there. The main problem is that there is a lot of empty room in the corners. Also, remember that the edges are first to go out and not all powercubes in a created map will spawn in every game