Controls

You play by swapping tiles. Tap one tile to select it, shown with a white outline, then tap a second tile to trade places with it. On a laptop, click instead of tap; a mouse click does the same job as a tap.

A couple of details make the swapping easier to follow:

• Selecting and swapping is the whole game. Tap or click a tile to pick it up, then tap or click any other tile to swap the two. Tap the same tile twice to cancel the selection without swapping.
• The position numbers printed on each tile show exactly where it belongs, counted left to right and top to bottom. A tile's border also lights up once it's sitting in its correct spot, so you can see your progress at a glance.

You solve the puzzle when every tile matches its number. The counter at the top tracks how many tiles are placed and how many swaps you've used.

The grid grows from 3x3 up to 7x7 across eight levels, so later puzzles take a lot more swapping to untangle.

Tips

• Work on one number at a time. Pick the lowest tile number that's out of place, swap it home, then move on to the next, since chasing one tile at a time keeps you from losing track of what you've already fixed.
• Finish a full row before moving to the next. Locking in an entire row of correct numbers first means you won't accidentally scramble tiles you already placed while chasing ones further down the grid.
• Use the lit-up border as your checklist. A tile's border lights up once it's in the right spot, so scanning for tiles that aren't lit tells you exactly what's still left to solve.
• Don't move a placed tile without a plan. Swapping a tile that's already correct just to free up a spot undoes real progress, so know where a tile is going before you swap it out of position.
• Start on a small grid if you're new. The early levels use a 3x3 or 4x4 grid, small enough to solve by trial and error while you get a feel for how the swaps behave.
• Look for a two-tile fix. Often the tile in your hand's destination is also out of place, so check whether swapping the two directly solves both at once instead of needing extra moves later.

Frequently asked questions