Temple Run 2

The formula hasn't changed at all since the first massively successful Temple Run, but the equally meteoric sequel features more obstacles, mine carts, and markedly better graphics. In case you're one of the few people who aren't familiar with the Temple Run formula, here it is: you run and jump across pathways, bridges and valleys, collecting coins and trying not to die. Upgrades can be earned slowly, or you can pay to get extras faster. Payment isn't necessary to enjoy: in fact, purists might be offended. Heck, consider it an excuse to start grinding achievements all over again.