It is nice but the controls are lacking, you can't control the player while jumping
and the point of this game is to jump on enemies, I guess if we can control the player in the air it will be much more fun. you can also make the player move a bit faster and more responsive, and maybe change the color of the player in each level, The Background is boring at least put some sort of sky or give it a nice color.
and you can easily add more levels just make some spawn points in an empty level and randomly spawn enemies.
This game has so many thing that can be added, But I guess keep it simple.
The Music IS SO GOOD.