Nice take on the top down shooter. Really like the pop sound for the shooting. Also felt like you introduced the new enemy around the right time, just as I was thinking “oh, another level, I’ll kill all the enemies” there was a spawner. For improvements, you might add power-ups for faster shooting, faster movement, or an AOE type ability or something. There’s room for additional challenge as well in here with faster moving enemies, ranged enemies, ammo constraints, etc. Great game with a solid base you can iterate on!