2048

Every swipe slides all sixteen tiles at once, and equal numbers merge when they collide. Reaching the 2048 tile is the nominal goal, though the board does not stop you carrying on.

Swipe on a phone or use the arrow keys on a desktop. Your best score is kept on this device so you have something to beat next time.

There is no undo, so a careless swipe is part of the game rather than something to take back. New tiles are nearly always a two, which is what makes an ordered row worth building: the small arrivals slot into the bottom of it and cascade upward. Your best score sits above the board as the number to beat.