Qwirk is three puzzles in one: a word puzzle, a number puzzle and a dot removal puzzle. If you like Sudoku, Rubik’s cube, crosswords or number puzzles, then Qwirk is for you.

Play is easy to learn. In a grid of scrambled letters, numbers or colored dots, select lines of three or more to remove them from the board. Outer puzzle pieces move inwards to form new groups. It looks easy but is deceptively difficult, even maddening, especially when you know that all puzzles have a solution.

-A grid of colored dots. Select dots of like color in lines of three or more to clear the grid. Outer dots move inwards to form new lines.

-A grid of digits. Select lines which add up to 10 to clear the grid. Outer digits move inwards to form new sums.

-A grid of letters. Find words in the jumbled grid of letters from a given list. Outer letters move inwards to form new words.

Use Undo and Redo to retrace your steps. Remember, all Qwirk puzzles have a solution.