Added some needed methods to the QActor class. One for moving a given distance in the direction facing, another for moving a given distance in a given direction, and one to set a fine-tuned rotation. Also made the overridden 'setLocation' method 'public' for setting a fine-tuned location.

@Green_Code, actually, no. All the energy would be transferred to the forward marble and the one doing the hitting would presumably stop. In real life, the only difference would be due to the roll of the first marble. Compare them to, lets say, billiard balls. The one doing the hitting would roll slightly forward. The only ways the hitting marble would reverse is if it had back-spin on it during contact OR if the second marble had more mass than the first (provided no other objects are influencing the system).

The storage is for scenario info for each user. Your program decides what data can be saved for each user. Refer to the UserInfo class API documentation for more info (Documentation link above followed by 'online' API documentation -- select UserInfo class).