I've been working on the design up until now, we've just started getting into the code. The basic idea is to modularize all of the abilities, weapons, and build structures available in the game into skill trees that players can advance through individually. So both teams would start out the same (as humans) and players would spend credits to upgrade how they please. We're both kind of busy though (and I'm not sure how much help I'll be code-wise) so I don't know how far we'll actually get with this.