Thank you for investing your time and giving some feedback.
About the yellow enemies, yes, good point, I should at least change its color or shape to something more aggresive.
I don't know exactly about the character position, right now he has more vision up, if I move him to the bottom, he would practically not see anything from bot. (Perhaps you encountered a bug?)
I'm sorry to hear about the difficulty :P, I've tried to make the game somewhat harder to force the use of rewind/resurrection, some friends of mine play it and had no problems, so I was afraid of doing it very easy. In particular where were you stuck? It would help me learn what should I balance if I decide to continue.
Thank you again for your feedback