The Animation Pipeline
The main thing is, using a script helps you to think the game through beforehand. If you are going to plan the game with other team members, another item that helps you converse and do some basic scripting is an item called a STORYBOARD.
The storyboard contains the basic tenets of what can happen - what goes from here to there - the storyboard is just a sketch of the main action. The storyboard is not the whole thing. You could storyboard a 120-minute film in less than 30 frames, simply because that would be 1 frame per really important point in the storyboard. You can pitch a major motion picture in probably less than 12 frames.