First online purchase when i get an xbox, just saying.
anyway, it would be nice if you could add a competitive portion, too, somehow, if you haven't already thought about it.Maybe it could be split screen, where you both start out in one corner of the level, and then you have to do a capture the flag like race to get the flag in the middle of the level back to your spawnpoint. :3
that's something I would definitely look forward to, if you could produce it.

p.s. yes, i sorta got that idea from the picture, but I wasn't clear on what was going on exactly, so i formulated this anyway.