Pokémon Go, an augmented reality computer game that aims to catch cute characters superimposed on surrounding scenery, has gone viral. Alex Hern of the Guardian profiles Dennis Crowley, whose career centers on location-based games like Pac-Manhattan, Dodgeball and Foursquare, and reminds that the game was 20 years in the making. Pokémon Go blends a popular game of the 1990s with Ingress, “a...