I think I would have chosen another button for firing when not using a gamepad. Using the mouse button to fire makes me feel like I should be using the cursor for aiming. However, the polish is super good on this game. Everything from the "Level X" at the beginning to the victory tune after completing a level. In fact, the sound design is really strong with this one. The game feels really alive because of it. The different music tracks, the victory tune, sound when you connect a hit on enemies... Feels very good. Well done!