I agree with what Marquis said. But let me add some more criticism. As you know, this is a jam, people won't be able to play your game for an hour or so. I played it for about 15 minutes where i died 2 times at orbs, and finally managed to get to winter. When i fell off to the start at the winter level, i just quit the game since i wanted to play more games. I wouldn't have quit if there were checkpoints. This isn't a rage game jam, this is a speedrun jam, extremely punishing gameplay won't make it easy to take risks and try skips and stuff.
Now lets get to the good parts of the game. The simple controls actually proved to be quite fun. I usually do not like floaty controls but in this one it gives a very nice flow to the game. Level design is also pretty good. Seeing how this is your first game, i think you are on a good track, as an advice, learn from this jam and add user friendly properties such as checkpoints for these games or hints for puzzle games in your next games. 

Cool movement mechanic and gravity. Just as a suggestion, maybe don't make the music reset every time the player dies. Would also have liked to see the theme implemented more, but still a very good job!

It was a bit hard to get used to the controlls, but cool game you know. I like the art style and how the face changes.