Simultaneously appear on the screen a random number according to the number of fingers you have chosen to play the early game and the random number that appears in red is the number of fingers you should locate on the screen.
You will have a certain time to put your fingers that you are assigned otherwise lose. In addition to this, regularly you will see a button on screen "MAGNESIUM" and you have to press it quickly and repeatedly until you have enough magnesium to keep climbing and falling.
To the extent that you reach a higher level the game speed increases, making a complete ROCK AND BOULDER challenge. The game is so simple and entertaining.