Very nice and polished entry!
I love the look, feel, and sound of this game! I was a little disappointed when I got to the walled off area after the double jump lol I suppose this is where we stop for now? I played around a little after and went backwards, and found a few rooms I guess I wasn't supposed to go into because it errored the game out. I have screenshots if you want/need them.
So, as I said at first, the look, feel and sound of this game is great! I love the abilities, the save points, and most of the enemies also. The more powerful enemies and the boss were both really cool too! I really like how you sort of made the boss advance in difficulty as you were fighting him.
Overall great entry!