Nice game!
You deserve more ratings, consider editing your Game Page to add a cover image (if you want) and maybe make the description a little more appealing (formatting, headers, see what you like). One thing that's missing in the "Controls" section is that you need to click to attack!
I liked the audio and how it changes, well played, and the graphics mix in well together - I know you didn't create those, but you used them very well.
Regarding gameplay, it's nice, but it needs to be clearer that you can click, double jump and slide. I also ended up falling through the terrain on multiple occasions: 1. on the start screen after a double jump, 2. after the green tree on the top world (fell through to hell) 3. after the big stone in hell
Some graphical bugs in fullscreen, like vertical lines appearing, also I couldn't see the red & blue squares on my interface (only when I fell through the world).