i think you should release it asap (but dont rush) the patching idea is pretty good
oh yea and prime, do you think that maybe a sequel or an add on to the game would be released sometime in the future? i like the mission generator for one reason, a lot of scrolling games typically have the levels become harder and if that is the matter, lets say you get stuck on a mission the generator could help you practice and come up with some moves to use in-game