The game crashed for me once but I beat it the second time though.
It's a bit buggy and I was able to skip almost every puzzle just by jumping over the obstacles. Jumping in general seems too powerful and needs to be nerfed, I think.
You have a lot of unique art assets here, you clearly put in a lot of effort. It looks nice.
I really do like the idea of changing the world by changing elements. It reminds me of some classic games like Chrono Trigger - changing the past - or A Link to the Past - moving between the light and dark world.
The puzzles are all "pick 1 of 4 elements, and 1 of them will work." This means that even without the jump-cheat, you can brute-force all the puzzles in a few seconds. I feel like all it needs to clinch the puzzle mechanic into something challenging is some interaction between the 4 worlds. A puzzle where a change in one elemental plane affects another.
A minor nitpick is there are a lot of interruptions to the flow of gameplay. Each tutorial/hint sign rips control away from the player and each element change requires switching screens. I hope you can streamline this more in the finished game.
You got an impressive amount done in the span of this challenge and I hope to see you develop this idea further. Good job!