Nice game. I think you did a good job with the optional paths leading to extra rewards but with higher risk.
Things I think you could improve:
The first one is the camera zoom in some places. Sometimes the player can fall down to maybe get a coin, and can't see the bottom is full of spikes because the zoom. That happened to me in one of the first levels. I saw a coin, went down to get it but died by spikes I couldn't see before jumping.
I like how you used the behavior of the slime blocks in level design, but at the same time, that behavior feels weird for a slime block. I was expecting something like minecraft slime blocks, that makes you bounce instead of launching you. I understand that you made all those levels with that behavior in mind, so I suggest you to change the texture of slime blocks to something that tells the player 'this will launch you'.
Thank you again for reviewing our game (Potionette) and good luck with your projects.