O Desktop - Use keyboard Left Arrow Key / A ad Right Arrow Key / D to move block
O Mobile - Use left ad right half of scree to move block

Adjust in the wall is a timing reflexive game, you need to move the free block to the correct position before it hits the wall. There is only one correct position for this block so there will be no mistakes allowed. Good Luck

For iOS:
Safari on iOS 8 and later supports WebGL 1.0, and on iOS 15 and later supports WebGL 2.0.

For Android：
Nearly all of them support WebGL