It might seem impossible, but the only thing impossible is impossibility itself. The Apple app Gravity Guy allows you to do the impossible.
The story is where the character is being put in prison, but breaks out and is on the run. You tap on the screen to make the character go from the floor to the ceiling and vice versa. You do this while avoiding obstacles like a robot police officer following you. There is also multiplayer. You can choose up to four colored gravity defiers and play as all of them by tapping on certain parts of the screen as you help them dodge obstacles.
If you want a game that requires focus but still has some action, you should get Gravity Guy.