Nice platform game!.
I like the graphics style (cartoon-like). I found the demo quite challenging (died a lot).
I also had problems with the trampoline like jumper. I managed to jump high enough once, but later could not and not found the rule for that.
What's missing? - hard to say if I knew a secret of a great game I'd do one .
I'll show it to my 5 old years son - I'm wondering if he would be able to play it