So far, this game does not really seem worth while playing. I can just hold the "->" key and jump across the platforms without even worrying at all about the enemies. Why put enemies in there when it's impossible for them to beat you?
There are a bunch of possible bugs I noticed in there as well. If I press the jump button fast enough, I can jump an unlimited amount of times. I also found that if you run forward into enemies, the enemies stick to you; although, this is kind of funny and has some potential as a gameplay mechanic. You also can keep from falling by moving toward walls in midair; which also has some cool possibilities for gameplay.
You should add more stuff to this game before you post it on this site. How about you add some things like more music and sound effects, more detailed sprite animations and level backgrounds, more power-ups and weapons, more of a variety of enemies in the levels, more complex jumping physics, and more rewards for defeating enemies and going to different areas in the levels? Perhaps even a backstory or a plot, as well? I am sure without a doubt that this game would be much better and more worth-while to play if things like the ones I mentioned were in the game. The more, the Merrier! (^_^)