The art director is the main man when it comes to the art side of game development and design. They are responsible for assigning tasks to crew and keeping the budget and schedule on track as well as covering quality control. The art director will answer to the production designer. I think the art directing role is very similar to that of a film role because it is for the same visual aesthetics even though they are made using a completely different process. I would imagine an art director would have to be extremely good at multi tasking and be a very ambitious and self motivated leader. They will be under a lot of pressure dealing with deadlines and budgeting and will have to be good at managing people and processes. This role will be very creative and highly demanding, I would have thought, getting to this position would require a lot of enthusiasm and they will have had to prove themselves in areas of not only team work and leadership but in artistic taste. They will be responsible for most of the visual side so sticking to a stylised and fresh look should be top priority.