So Funny Story: During the Epic Boss encounter I managed to kill all the bosses but wound up dying to the last hammer. The game just freezes. If You axe me there's just not enough room in the game for THAT much peace.
AFter you finish a level it won't let you leave but it pretends your guys is still at the right of the screen fighting. As such you keep gaining experience even though you're dead
erase all data and it should work.