10101

- Game is named for its time 21 seconds in binary and minimum score of 21 points

- you will be shown a series of number images (showing either 0 or 1) and you should swipe them left or right as shown before starting the game.

- In any full round, image containing 0 must be swiped either left or right and same in case of image containing 1.

- Any wrong swipe or move (e.g., if you move image containing 1 to right but if you were asked to swipe it left, it is considered wrong move) will terminate that round unless your score is minimum 21

- While game is in progress, number images may contain directions which are only to deceive you.