WOW! What a game! I really enjoyed the unique mechanics of the game and how the levels are designed to be interconnected and the player can reach those areas when they acquire a new form. The music reminded me of old Bejeweled 2 / 3 soundtracks for some reason.
The only 2 feedbacks that I have would be to have different / remappable controls as I had issues with my Arrow Keys so I had to play with WASD and maybe an options menu to lower the music volume.
Overall, 10/10 awesome job!