Very nice game! Congratulations :D
Fits the theme very well, good length, I liked that the jump had a short and a long version. The touch of the key following you is very good.
Some tips:
1-When you use pixel art on godot there is a filter that blurs the sprite. Look how to disable it, is very easy.
2-When you make a platformer look for coyotee time and jump buffers. Simple ways to improve the feel of the controls.
3-Use the limits properties of the camera2d to avoid the player see outside the gameworld.
4-Try to make clear the method about how to advance the level. Is quite unclear how it is currently.
I hope you find one of these tips helpful for you.
Great work! :D