With games like Wolfenstein 3D, Doom and Quake, computer programmer John Carmack is widely considered as one of the fathers of the popular—and sometimes controversial—first-person-shooter genre of videogames. Even with all his success, the 35-year-old remains at heart a tinkerer, shown by his longtime interest in rockets, and, more recently, games for mobile phones, including Doom RPG [role-playing game], a translation of the PC classic.

NEWSWEEK‘s N’Gai Croal caught up with Carmack.