About Unblock

A six-by-six yard packed with blocks, and a gap in the right-hand wall. The red block has to reach that gap. Every block slides along its own line and nothing else: the ones lying down go left and right, the ones standing up go up and down, and none of them ever turn. Drag a block to move it, or tap it and use the arrow keys.

The difficulty is that clearing a path is never one move. The block in the way has nowhere to go until something else moves first, and that something is usually blocked too, so a hard yard is a chain of five or six preparatory moves before anything useful happens. Working backwards — what has to be true for the red block to get out, and what has to be true for that — beats shuffling pieces and hoping.

Every yard here was checked by a solver before it shipped, so the shortest solution is known exactly: it is shown while you play and your result is rated against it. Three stars means you found the shortest way out. The daily challenge gives everyone the same hard yard and ranks the day by fewest moves, with the clock breaking ties. Undo is unlimited, and a hint will point at a block that is genuinely on a shortest path rather than one that merely looks useful.

Tips to win

• Work backwards from the exit: the red block needs a clear row, so ask what has to move out of that row and where it could possibly go
• A block with no empty cells in front of or behind it is not the problem; find the one whose path is nearly clear
• The corners and the outer columns are where blocks get parked — leave room there before you need it
• If you are stuck, undo three or four moves rather than one: the wrong move is usually earlier than it feels