FireFox - This is an Old Model I made years back for a Game Project [ That I never got to finish. :( ]
It's Alvin, Simon and Theodore [ Based on the early Ruby-Spears Animation, Not the Chipmunk Adventure Era ].
Basically, You could switch between them as they had their own ways to overcome obstacles [ Ways which I have forgotten now.. ] and the Levels were based on Episodes from the Series. You could talk to familiar characters to do Side Tasks too for bonus points.