This was an utter delight! Really took me back to the good old days of raging at games like Mega Man and Metal Slug. The level of detail that's gone into the backgrounds (and foregrounds) is really something, there's so much to admire here.
The controls are nice and intuitive (I kept pressing the wrong buttons because I'm an idiot, once my brain finally got into sync with my fingers it was fine), the demo level on display is challenging but not to the point of being impossible (or even seemingly so), and the boss fight was excellent!
I'll definitely be watching out for more of this brilliance, keep up the amazing work =)