Sniper Elite 3 by developer Rebellion. Before you get too jealous, it sounds like Brooker's cameo will be as an NPC, and Brooker will more likely be a snipe-ee than a sniper.
Rebellion founder Jason Kingsley spoke highly of Brooker in an associated press release, and said his inclusion will be a way to thank Brooker for being such a vocal fan. "At one stage it seemed like Charlie mentioned Sniper Elite every few weeks in his Guardian columns and we're incredibly grateful for his support, so this seemed like the perfect way to say 'thanks,'" Kingsley said. "We really appreciate Charlie championing a British-made game series."
Lest that sound like celebrity endorsement money talking, Kingsley was quick to downplay such corporate motivations. "You can buy endorsement all you want, but gamers can tell the difference between a genuine fan and a celeb that is happy to get a payday."