The actual gameplay is very cool and super challenging. Between the retro graphics and high difficulty, this really feels like a good old NES game.
Unfortunately, the ads are constantly taking you out of the experience. You will most likely be button mashing every time you die, and this will, almost every time without fail, lead you to accidentally clicking the pop-up ads that show up when you die or beat a level. This switches you over to the App Store. It is extremely annoying and just takes you out of the game completely. If I could, I'd pay a couple of bucks to get rid of these stupid ads, but there is no such option.
Maybe it'll be more playable in a future incarnation.