Really nice! I like that you went for telling a story, even in the limited time a jam provides. I also think the shapeshifting mechanics are cool - each shape having unique strengths makes it fun to solve puzzles (though I’d love to see some more tight level design in that regard). I did find the controls slightly unintuitive though. Maybe I just had to get used to them, but I wonder if instead of giving each form a button, you could have mapped them to more natural controls? Like maybe have one button to toggle between circle and square as the most common, then “double jump” to turn into a rectangle. And maybe a dedicated “attack” button for the triangle? Idk if that would actually be better, but it was the first thought I had.
Overall, I really love the idea and it would be cool to see you do more with it!