Nice game! I have just some suggestions to make the gameplay feel more fluid:
- Increase the range of the attack. Now, it's hard to get close enough to the enemies without touching them.
- Automatically moving X pixels forward when attacking (feels more powerful)
- Don't get hurt by stunned enemies.
- Feels unfair when the bullets pass through the walls.
I tried a lot of times, but I was not able to finish the game =P