That's a nice game. I made it through, lost a gazillion lifes though.
Difficulty feels about just right.
I discovered a little flaw in the last level.
I got stuck in the checkpoint sprite when jumping below it to collect some coins. Also at the same position, once the checkpoint is activated and I am not stuck I can't get the red blob to collect the upper row of coins below the checkpoint, it doesn't want to jump in that narrow part.