Drew Davidson likes to play with blocks in his sandbox, as he demonstrates in a show-and-tell to interactive media colleagues. In this case, the playground is an online game called Minecraft, a two-year-young internet sensation with millions of followers, developed single-handedly by a programmer named “Notch,” (A.K.A. Markus Persson). Walking the audience through the game, Davidson shows what makes it irresistibly playable for so many. He also shares his interest in talking “about games in a formalized way, other than saying this game is ‘awesome.’” Davidson wants to capture the game play experience, which he believes to be “radically different from anything else, because agency is involved.” Minecraft takes place in the course of a 20-minute ‘day,’ and in spite of crude graphics, rapidly immerses a player in an entire world where all the features of the landscape can be built or manipulated for different ends—an activity called ‘crafting.’ Players can chop blocks to create shelters, whack trees to make axes, pull wool off of sheep and grow wheat. This is not a simulation game: bad things happen at ‘night,’ so there is an element of suspense and strategy.  The two elements of “creativity and survival,” says Davidson, add up to a classic game play experience. Plus, he says, Minecraft “breaks all the rules:” it lets you play for free by yourself, learning how to craft by trial and error; interested players can contribute new elements because the code is freely available; and multiplayer groups can get together online to create projects and pool their worlds. It is “snackable, just like Lays potato chips,” says Davidson. You head for the game frequently, but at the same time, the “complete play experience fits easily into life,” because “it is simple to get in and out of the game.” Minecraft meets all the mechanical, aesthetic and design criteria for great gaming, says Davidson, enabling speedy involvement, deep immersion and long-term investment, and has ...