At first as I was pushing it up the hill and met the initial dead-end, I thought this was a giant troll where you really just push the boulder up and down that same hill, but after you make the initial jump ... such a nice surprise and I was pumped to keep going.
Some fiddly gravity on the player character, but hey, it's a jam game. I thought the art was really nice and cohesive and just that extra attention to your background layer made the whole thing more immersive. Good music, some sound effects would have helped sell it all, but overall this was one of my favorite experiences in the jam.