I'm having the same problem as DatONEfoo. A flying creep has somehow ended up outside where nothing can get to it and level 65 won't advance until it's dead.
Very interesting dynamics on normal lvls, but could use a few more and a good spell checking as well. The endless mode needs some tweaking to be playable, it's no fun to only last 20-30 seconds in a mode called "Endless."