Great style and execution! Good luck with Steam also.
Would personally challenge a few of the design decisions, such the (keyboard) button mapping or the health-for-morphing concept (is the limit on morphing really necessary? Especially in tutorial it feels odd to morph wrongly and have to return to the checkpoint for health)
Only played some of the tutorial I have to admit, perhaps those things are justified later.
Either way, looks good, controls feel good (when used correctly), level design seems to make sense.
Congrats, cool project,