The 1999 applet's game, re-implemented in JavaScript. Four skins, unlimited undo, and a solver that answers in the fewest moves there are. What this is, and where it came from
Slide a tile by clicking it, or with ← ↑ ↓ →, W A S D or I J K L. U undoes, N shuffles, R restarts, S asks for the shortest solution and Space plays it. On a phone, tap a tile, swipe the board or use the pad. The arrangement and the skin you leave on are remembered in this browser.