Sentence:  It is, in itself, a beautiful little game, but what it really indicates is a new way to create game controls: by simulating muscles rather than arbitrary forces. The rig in Ski Stunt Simulator is a controlled, active <WSD>ragdoll</WSD>. 
Meaning of the word marked with <WSD> tags:  A model consisting of a set of connected rigid bodies that can collapse in a loose, natural manner.