It was initially a real game made after someone made a joke, I wouldn't say it was ever a joke, but it was at first a fun game made for fun between friends, and then Keits ran it at a few tournaments last year. He eventually Kickstartered it to make it into a real game, and then it got pulled after it was purchased by someone.
Fast forward to this year, and his employer Iron Galaxy was revealed as the company behind it and they are making it into a real shipped product. It's still a fun game, but completely redone and will be released on PS3, Vita and PC this summer. (PC users goto www.greenlightdivekick.com to help it get on Steam)
The way I describe it is that it takes the final moment in a fighting game when the two player's lives are both down to a final hit, and the next hit wins. But instead of worrying about six buttons and a stick, all you have is Dive and Kick. So it's super accessible but also deeply complex when you start working in the character differences.