The art on this game, besides the menu page, is pretty swell, but I do feel this game is lacking a lot. Mainly variety is something that doesn't really make an appearance in this game, overall it's just jumping over enemies while grabbing some points, it gets boring really easily. What I'd try to do is add some more originality and variety in the game. More enemies, with different AI's, as they are only throwing at the moment. The jumping animation could also use some work, I don't think the way the character jumps right now is very convincing, maybe you should change it into someone with one of his knees in the air. Also adding a few more frames for a nice animation would really do wonders.
All in all, it was a nice game, but really nothing special. Nice job on the sprites, but that was pretty much the only really good thing about it. Keep it up, though.