Welp I don't have much to yap about. It's a very cute idea!
The only thing I can bring up is not really an issue I guess? It's just that the solution to every level is to make a wheel; but that's part of the core idea of the game and I'm not really sure what you could do against that.
Maybe making the shape "flatter" makes it more slippery? (idk how you would even code that in xd)
Or maybe you can control the rotation of the biscuit like a motorized wheel and then you need to eat the shape in a different way to be able to cross each level? (more puzzle game-y)
But again, this "issue" doesn't really take away from the game and having different shapes for the biscuits helps counteract it a little bit.