I agree with xero entirely. Building the game is our first priority and multiplayer is the goal. We're not averse to singleplayer though (indeed, I'd love to program a singleplayer campaign system for this) however it'll all come down to time and resources. Singleplayer also requires a bunch of new stuff to learn so if we can bring in a specialist team to help put that aspect together I think we'd seriously look into that.