I didnt expect a boss fight :o .Great idea executed very well. The puzzles are fun to solve but there are some dificulty curves. The main mechanic is fun to play with. I often found myself missing the wave by a little amount and waiting for the reload. Maybe adjusting the reload speed or the hitbox of the waves can make the game more accessible.
Other than these great work. I can see myself playing this if it was a full game you should definetly work on it :D