Dino Run
In this game you have 2 dinosaurs, a big pink one and a small blue one. In the beginning the small dinosaur sits on the big one's back and you control both of them with A-S-D-W keys. You can press Space to make the small dinosaur jump off the big one's back. From this moment on you'll be controlling the small dinosaur until you get back to the big one's back (to do it get close and press Space) or switch to the big dinosaur pressing Tab. Controlling the dinosaurs separately is useful for turning on switches in different places and doing similar things a single dinosaur can't do.