This was a really cute little game! I liked the concept, and the two layers of gameplay (getting the jam and then finding the other half) was really compelling, and has a lot of potential. I definitely struggled with the movement, I almost thought it was broken at first. Only being able to jump is interesting, but I don't think that is presented particularly clearly and it's a little unwieldy. I also wasn't quite sure what to do when it came to the jam jar, I was standing on it and then besides it wondering if there was a certain input I had to press before I stumbled into the jar and got jammed up. I was able to figure out that I had to progress through the side area, but I can also see how that sort of thing could be missed. Perhaps an earlier level with both the jam and the other half would work better to introduce the whole concept and function as a basic tutorial, that could help! Overall, a charming idea with a lot of heart. I hope you do finish this after the jam and even expand it, there's a lot of interesting possibility with puzzle design. Good job!