I liked how you changed gravity just by jumping into the void. Sometimes I would get stuck though, because I couldn't jump and wouldn't have enough momentum to escape. It was a bit hard for me to get past the bullet things that shoot horizontally because they come very fast and without any warning. It was also a little hard to tell which things would hurt me and which things were fine, maybe more color coordination would help with that?
Honestly though, for only 2-3 hours and this being your first ever game jam, I'm impressed! Congratulations on finishing something and submitting it, there is always room for improvements, but actually making something is how you get better and learn :)
Edit: Okay I just managed to beat it!