One thing that would be much more practical for the character would be if he used the momentum of the somersault to stand up, instade of first stopping and then rising up.
It's a basic move that I'm sure you've done in gym class.

I think the jump needs different arm movement. Now he's flapping his arms out sideways, when jumping most people swing their arms from the back and forward/upward to gain more momentum. This looks more like a getting down from a rock or something. Still great.

You use like 4 purple colors, but they look like one, up the contrast. Where's the light coming from? Apparently nowhere because everything is blanket/pillowshaded.

You will not learn much when using a template. By the way it's made by Showkaizer, not some HK.

Mathias, every thing is correct but that's not a very reader friendly post, it's a wall of text.
I don't agree on making the same avatar again though, sometimes a fresh breeze is good. It's one thing when you're established, then it's wise to keep the logo/mascot. But when you're not, it's ok to change.
Look at really old logos from well-known companies, they usually look completely different.