There's a bug when the border is turned off. If you run across the screen's border and keep the key pressed, the controls sort of lock and then come back.
Boss is a little disappointing. Quote at the end should say, "You have just beaten combo killer. You sure gave a good fight..." The path way on the left , second up from the floor doesn't have enemies that come from both directions. Once you've got the magnet big enough and a gun that's fast enough you can just sit there and collect cash.
yeah trying to fix that