Press w,a,s,d or the arrow keys to move and space to jump! Note: I have completed every stage so if you think something is unbeatable, it's not.
The storyline is: You are out on a walk and venture inside a cave, a boulder blocks the entrance and a stone from above knocked you out. When you wake up you remember nothing apart from the urge to travel in a particular direction. When you make it to the sunlight, you remember everything and that is the end.