Hi,
nice little game, well done. first jump took me several tries to finish too, missing some sound wile playing. A little sound when jumping would make a big difference. Also, make two more layers in the background with a parallax effect and you will notice this will be little work with a big impact on how your game looks.
Please feel free to try out my game and rate it here: https://itch.io/jam/cgj/rate/474542
Many thanks,
Kris