The instructions are in the game but if you need a reminder of what the blocks are

Blue: Touch them when you are together to go to the next level

Green: You can only pass through it when you are together

Red: You can only pass through it when you are NOT together

Magenta: If one of you touches it then both of you restart

Light Cyan-ish: Only white can pass through but you cannot pass when you are together

Dark Cyan-ish: Only black can pass through but you cannot pass when you are together