Thanks for playing! And we're so glad you enjoyed it!
Yeah, we ended up spending a lot of time just tuning the controls and physics/mechanics and stuff, so not a lot of time was left for us to throw levels together. We also noticed the steep difficulty spike on that last level... oop.
As far as making things look polished in Godot, don't worry, it wasn't Godot, it was us! Our "artist" is actually just a musician with MS Paint :-)