Solving every puzzles with the given bullets was really nice, solving every puzzle without using a single bullet was GREAT! No sarcasm, it was actually really fun!
Really great game and concept! I can see it easily expanded into a longer game. A teeny tiny quality-of-life change I'd suggest is making the screen close simultaneous to the box explosion, it takes just a little bit longer than necessary to restart the level right now. Great job on the game!