Movement controlled by mouse only slow, fast any direction ?

I was playing an old game last night and realized you can controll all movement with the mouse, well except fighting moves which require pressing a couple keys.

The mouse controlls turning and forward actions. I thought you had to hold the shift key to slow the movement down, however, I moved the mouse to back a bit and didnt move it.

The character stopped and then when I move the mouse forward, she moved slowly, not running. To make her go into run I just moved the mouse a greater distance and that started her off running.

How would you do that with python or the bricks.

Yes I am asking for some one to do it for me. Smile. Its a great option for control for everyone to use.

Thank you. Have a great weekend. Schools out, the suns out, everything is good…

LOL, thanks Social, good name.

Hmm, very interesting. I had seen this in some other blend, but didnt understand it. Thanks much. Now I get it, and another door opens.