Ah, the game that launched a million endless runners. True, Canabalt ($3) might not have single-handedly invented the runner genre, but it was the first real smash, delivering a startlingly intense experience despite the simplistic pixel graphics and teeny-tiny character. Even today, it’s great fun, testing your reflexes at a constant clip as you try to leap between rooftops, into tight office windows, and over fast-falling alien ships.
In fact, while Canabalt has kept its core simplicity, the game has grown over the years: Now it has several alternate game modes that tweak the hazards you’ll face, along with multiple runners to choose from. It’s still monochrome and delightfully tough, however.