Hey byte, nice entry! I liked the difficulty progression and the core idea is very nice aswell. The game is easy to understand and pretty straight forward.
A couple of things where I'd see room for improvement is in some minor things. I'd recommend you to implement a "coyote jump" - that would allow the player to jump even if they're technically not grounded anymore. That makes plattforming usually feel a lot smoother and less frustrating.
The player can't jump if they're small and between two pentagons (probably because there is no floor directly underneath them?), that feels a bit clunky at times, especially when there is time pressure on the level.
When it comes to colors I can't recommend enough getting into color theory a bit. There are loads of tutorials on youtube and it does make a huge difference.
Good job on your finished game!