The story was interesting. I loved it. And I enjoyed the easy levels to just break up the story.
I wish you could shoot through the spikes. You should defiantly be able to shoot through coins. It seemed a bit frustrating how you could die by just slightly touching the spike.
One time I re-spawned on an enemy and died. And when I re-spawned all the enemies were gone that I killed. Maybe have them spawn at a set place when I spawn.
Shooting with the Enter key and Using Space to just is hard. I like using Z and X.
Keep making games!