I really like the idea of transforming the character to adapt to different situations using various elements. However I did notice that the fire and water transformations are only used once, while most of the game is completed with the tree form. It seems like a lot of time and effort went into building the form-switching system, which might have left limited time for level design.
I also wanted to mention a couple of other things I noticed: in the water form, you can pass through fire (I wasn’t sure if that was intentional). Also, some enemies die on their own by walking forward and falling down - I never managed to reach the axe-wielding enemy :D
I also want to mention that the game sounds nice, and the element animations are really well done. I’m looking forward to seeing how the game develops with more levels and creative uses of the elemental mechanics!