The game is all about mining bitcoins so you can afford to turn your crappy apartment into a geeky bachelor pad filled with hot tubs, arcade machines, priceless art, and robot butlers.
You get money by tapping the screen. And then you can spend money to make more money when you tap. Or you can spend money to make money even when you're not tapping.
No, it's not especially deep. But it is fun in a mindless sort of way. And one of the wonderfully clever things about the game is the way it turns some of the classic free to play shenanigans on their head.
While most games bombard you with adverts until you pay to turn them off, in Bitcoin Billionaire you can actually elect to turn on adverts and other irritations for a while if you want to boost your cryptocurrency influx.
Anyway. It's free, so you can download it for yourself and see if you think it's a work of art like Rob, or a pointless waste of bandwidth like me.