This is definitely a fun little game, I enjoy all the different kinds of powers you can use against enemies very much, however I feel like they’re a little easy to defeat, especially since there’s really only one type of power/elemental shield that protects against a power namely the fire shield, so how about adding more types of shields that protect against the other powers like Lightning, Ice, Water, Rock and even other powers like Telekinesis, Poison and Fat/Grow power, in that way you really have to switch between all powers instead of just using one all the time.
How about adding some actual environments to make the levels come more to life, like desert, forest, mountain, volcano, snow and more.
I really love using all these different kind of powers, you have basically included pretty much all powers that fit within the game, I don’t think there’s really any more (elemental) powers that could be added, maybe a Thin/Shrink power?