I really enjoyed this game :) It was very engaging and loved the art style
2D Platformers is my favourite genre so here are a few suggestions I have.
+ Players are able to stick to the walls mid jump/fall. Adding a Physics Material reducing the friction should fix that
+ The jump detection seems to be a little to generous, this allows every player to double jump if tapped fast. Tweaking the detection radius with more testing would help.
+ Increasing the gravity scale would make the characters less floaty. In my opinion, having responsive characters with quick move actions fits this puzzle platform level design.
Overall thoroughly enjoyed this and look forward to seeing more.