Hello. Nice art, and music (you used Bosca Ceoil, right? Me too :)).
I have some critiques, let's get into it:
I don't know if it's a choice, but the controls do not feel in any way responsive. The space button must be pressed a LOT to work. Sometimes I tried to wait, pressing in intervals, and did not work. Sometimes I pressed space at the speed of light, and didn't work either. The same goes for the attack. The solution I found was jumping and pressing space/leftclick, that seems to work sometimes, except that when I jump the camera goes underneath the ground, and I can't see the level.
When I finish the level with the enemies, I kept going back to the start, and it keeps forever like this.
As I said, I liked the art and the music, and I would really like to see the game transformed into a full game, but at the state it is now it's so frustrating that looks like it can't be played.