Played the demo through to the end. Encountered a problem when the first boss appears... the screen moves and I disappear off the left side and can't move fast enough to reappear, but I can continue to follow and shoot from off screen. You could fix this by not triggering the boss to appear until the player has walked over to the far right of the screen. The second boss was much more fun with the moving tables to stand on, but I did find you couldn't avoid being hit during some of the boss movements across the screen. Fix the boss issues and add a bit more enemy variety in the levels and you've got the start of a good little game demo. Nice work!