Great theme implementation and use of Monsters pack haha, I was planning on having them in my game too.
It's just the right size for a jam, I enjoyed it from start to finish.
Few crits:
- A crosshair would have been nice :P
- The tutorial confused me into thinking the gas enemies should be avoided instead of killed.
- The tutorial was switching a bit too quick for my reading, I didn't understand why not let the player switch tutorial cards?
- I think it might be hard to implement, but the spaceship couldn't aim higher than a certain degree. This created the need to either search for angles from which I could reach higher up enemies or get hit by the ceiling in order to be able to shoot them.