Well done! Fun, catchy music, nice pixel art. Certain weapons and combos are a bit overpowered but that's an easy fix with some care. The text was a bit bland, and the tutorial could use a bit of work, maybe having the player actually combine a weapon and shoot it? Enemy spawning is a little bit random, sometimes the spawns are amazing, other times they spawn right next to the player and on top of other enemies. The difficulty might need some adjusting too, I only got hit once and that was a the very beginning. Keep it up dude!
P.S. Nice gedaan Habrambe ;)