In the console version of the game, he first appears speaking to Bond via earpiece in a helicopter while remote controlling the V12 Vanquish until Bond and Dominique take control of it. Q is then heard giving Bond instructions. Q can be heard occasionally giving hints during "The Exchange," but doesn't play another somewhat major role until providing Bond with a way out of Austria.
He can be heard peridocially during "Double Cross," particularly when he informs Bond of the addition of the shaver to his inventory. Q is next seen via message on the way to Phoenix International, where he informs Bond of a few new gadgets. Due to the precision and caution that must be used during "Night Shift," he makes gives many hints and words of warning throughout the mission. His next major appearance doesn't occur until the mission "Deep Descent," where he is present on the boat with Bond and Alura McCall and gives many more tips throughout the mission. Once the two reach the island, he continues to aid Bond with hints. This is his last apperance in this version of the game.
In the PC version, he has fewer appearances. He can be heard suggesting to Bond to use the Q-Grapple if the player chooses the back way in during the first mission. His next appearance doesn't occur until the ride to Phoenix International, where he informs Bond of new gadgets. He also gives Bond hints and words of caution throughout the mission. This is his last appearance in this version.