Cosmo Run

From the main screen, click on the Play Together option. You'll now have to use two inputs to start a multiplayer game. As noted in the Roadmap, you'll need two available inputs to start a multiplayer game out of the following three: touch-screen, keyboard, mouse. After clicking on the Play Together option, player 1 and player 2 will have to use two of these options to select to start the game. The game will start and you can both die immediately to end the run. The achievement will unlock immediately after the run ends.