Controls are fine, but you can't move diagonally.
The level design is very good, but sometimes is frustrating, since if you fail a puzzle or you fall down you have to go all the way back from the start.
Anyway, good job and I hope you keep upgrading it after the jam.
Here's mine if you have a moment to play it.
https://itch.io/jam/gmtk-2019/rate/463337