Very cool entry! I love the variety of weapons, although I felt like the laser is a little too overpowered because I ended up using it for most of the game. The enemies getting bigger when taking damage is a cool mechanic because it makes them harder to avoid and feels satisfying. I also like how the levels are fully destructible.
The boss fight at the end was very cool, but at first I thought I wasn't doing any damage because it wasn't getting any bigger or giving any other visual feedback, until I noticed the health bar in the corner.
The music and graphics are nicely done and fit the tone of the game very well, I especially thought the pixel art on the final boss was really good.
Two (possible) bugs I found: At one point I reached 0% health but was still alive until I took another hit, and also it seemed like the game crashed after the final boss.
Overall a solid entry!