[jediaction]

If you mean restart by "restart the application" then that is not possible with normal Alice. It might be possible with Jython scripting though(I don't know much about Jython so to find that out, talk to Arty-fishL). You can make positions reset with button clicks and when the button is clicked, all the object move to there origional positions and then the method restart. But, it all matters on how you make your game and what kind of game it is. Hope this helps