Just seen this RTS-FPS game called Apox on Steam for £8.70GBP. Reading the description, watching the videos, and seeing support for up to 32 players makes me think this is the sort of game we've been looking for among our group of gamers (we tried Alien Swarm but being only 4-player co-op, it left some of us out for some games). Additionally, working until late, this gives me the option of going single player. I love facing off bots in SC2 for example and improving my tactics. Seeing this quite revolutionary game style seems like it might appeal to me for that sort of time.
Official Site: http://www.apoxgame.com/
Anyone tried it yet?