The controls is rought, but the big issue are the gui, should add transparency to it or sometthig allow you to see the upcomig foes, theey end hidden begin the bar.
Alternatively you could put a rect background and make the foes consider they are out of the screen if are behind that(look for a strategy game like warcraft or age of empires, the older ones that were preerendered it gonna be more clear what i'm trying to say).
if you only could enable a extra skill you could nerf it and simply unlock it in level one(thought i get is not the intended is easier to display you idea that way in a demo or prototype, they are mean to be a atention catcher, adjusment gonna be made over it and the ability could be completely replaced or set a levels between them).