Fun platformer! My favorite part was the bubbles, which added a very unique gameplay style to the game and set it apart from other games in this genre. I also like what you did here with the theme - I certainly wouldn't have thought of looping around a trail, but I love how you made it into a game.
The trail changing every loop also helps the gameplay experience never feel stale or repetitive. Good development decision!
As for the graphics, I think they were cute, but a little inconsistent. The background was a brown blob, while the mountains were flowing and looked almost painted, and the level was solid and simple. All the pieces of art look good on their own, but don't fit together too well. Consider a more consistent approach as a next step.
The level design was another plus for me! You used the buble mechanic liberally and I completely agree with that choice - it goes far to highlight the unique nature of this platformer. The design of the level was clever, intuitive, and logical.
Nice work! Congrats on submitting to the GMTK Jam, which is a huge feat in itself :)