I love it! The main character sprite is cute. The shine on the gems are quite nice, and the background is professional looking too. Finding just the right assets to bring your ideas to life is an important skill in game jams (or hobby game dev in general), and you nailed it.
The background music is nice too, pleasant but not too distracting.
And the game is easy to pick up and have fun with right away, which is perfect for a game jam. I love how you can jump up to get gems a little earlier; I think this is an important part of the skill.
Nicely done!