You and your character will have to go through a difficult path through numerous obstacles. Sometimes decisions will have to be made with lightning speed. There are ramifications in the game. Some lead to a dead end, others continue the game. It's up to you to decide.
On mobile devices, touch the screen to jump, and on a computer, left-click. To get off the platform without jumping, just keep running, the character will tumble down by himself. H - hide/show the mouse cursor.