Lol I don't really control them, I just see if there are any that haven't been submitted from time to time as well as post in Isaac's threads when they get published so he can keep them up to date. =) Thank you though!
Sorry you cant do that challenge thing like you could on XBLA. Any level I would challenge you would be one you already have. Also I do not have the full version of the game. Only the trial. Sorry. Officer is one i had trouble with. Try the level I mention in the guide.