Sgt Crispy writes, "XKCD creator Randall Munroe, has made a spiffy little hoverboard game. Looks to be small, however, when you realize that boundaries are made to be broken, A massive world opens up to be explored."
He's not kidding about the "massive" part. A few minutes' fiddling has convinced me that a) this is a huge piece of playable narrative and that b) it is a narrative, with a complicated, sweet story that's every bit as impressive as the Hugo-award-winning Time. That sound you hear is the XKCD wikis going bananas as Randall's readers go to town sleuthing out the full story.