Could be a good surprise in the end but the change from genre (to a FPS) is not really promising.
Makes me think of X-Com Enforcer. Not really a bad game by itself but no on par with the other X-Com titles.
It would be nice if the other characters (from the co-op mentioned) could be AI controlled and allowed a human player to switch control between them at will. A bit like the Hired Guns 3D beta does.