Slide the blocks to move the blue key block to the green exit area. Blocks can slide up, down, left or right into empty spaces. Only the key block can slide into the exit gate.
On a touch screen, a tap does what a click does.
Use the mouse or a finger to drag the blocks around. A block follows the pointer and settles on the nearest space it can actually reach, so you can aim roughly and let it snap.
You can also play entirely from the keyboard. The arrow keys move a red cursor around the board. Press Enter or Space on a block to pick it up: it lights up, and the arrow keys then walk it one square at a time through the spaces it can reach, refusing any step it cannot make. Press Enter or Space again to put it down, or Escape, Backspace or Delete to hand it back to where you found it.
However far a block travels in one journey, by drag or by keyboard, it counts as a single move — and sliding it straight back where it came from takes that move off again.
Generating a new puzzle takes a moment, and longer on the larger sizes — the generator solves the board from scratch after every change it makes, to be sure the puzzle it hands you is still solvable.
Hint shows the next move rather than making it. No move in Slide is forced: every move leaves a board that can still be finished, only in more moves or fewer. So the hint finds a shortest way to get the key block out and shows it to you a few moves at a time, each one with what it is for.
Most of Slide is getting other blocks out of the way. The key block can only move once there is room, and making room for it usually means moving a block that is itself stuck until a third one moves. The hint shows that errand one move at a time, starting from the far end: each move makes room for the outlined block, and that block is the next one to move. When the key block has room, the hint moves it and tells you how few moves it can now be out in. Now and then the room a move makes is for a block that moves a little later, or a block stops part way and moves on once there is room.
Every move the hint shows is on a shortest way out. Play some moves of your own and ask again at any point: the hint finds a way from wherever you are. The search has a limit, which no board as dealt comes near; if a position were ever past it, the hint would say so, and Show solution… would finish from the board as it was dealt.
These parameters are available from the ‘Custom type…’ option on the ‘Type’ menu.