×How to play: using the fewest moves, form a Word Square (the same words across and down) with the tiles
select a tile to move, then select another tile to swap it with
tiles in the correct spots are the darker color and immovable
The across and down aspect of a Word Square makes it symmetrical about the red dashed line shown below. Letters not on the line have a twin across the line.
Word-by-Word automatically selects and moves these twin pairs.
Puzzles begin with some tiles in the correct spot(s) to get you started. The easiest level has 9 starters, as shown below. There are 13 dark tiles, but 4 are twins.
Harder levels have fewer starters with the hardest having just the center one.
The movable (lighter color) tiles are arranged at the start such that choosing the correct swap will result in both tiles in their correct spots.
So on the easiest level, starting with 6 twin pairs of movable tiles, you could solve the puzzle in just 3 swaps, if you choose the right 3.
Similarly, the next level can be solved in just 4 swaps, the next in 5, then 6, and finally 7 swaps for the hardest level.
In Challenge mode you must solve the puzzle in the alloted moves plus any banked moves.  Banked moves are those remaining afer you solve a puzzle.
Everybody solves the same puzzle in Challenge mode, but can select their preferred difficulty level. Harder levels do provide the opportunity for more banked moves.
Puzzles are released twice a day at 0:00UTC and 12:00UTC