Thus, the first title developed from scratch for the iPhone, Doom Resurrection, was not a true first person shooter. featured impressive art and graphics taken from Doom 3, but limited the player's movement to event-specific actions. Doom Resurrection was designed with what Carmack perceived at the time to be the iPhone's limitations. However, experiments with control schemes in Wolfenstein proved that movement and aiming could be handled on the iPhone platform.

Carmack is especially excited to see how people respond to the newly-released for the iPhone. He believes Doom has better default controls than Wolfenstein but he admits he "sort of regret[s] not having a button to go back to Wolfenstein compatibility." But "you can get 95 percent of the Wolfenstein [control] experience" in Doom, Carmack adds.

Doom didn't take long to develop and in fact was ready to launch much sooner than its early November release date. "I was trying to be responsible. We could have had it out after Wolfenstein Classic," Carmack said.

But while Carmack enjoyed the development phase of Doom, there were still some challenges to confront. Many levels in Doom require players to aim in multiple directional axes since enemies are at varying heights. To address this gameplay issue, one of the major differences between Wolfenstein and Doom is the number of instances where the computer helps the player aim. Carmack programmed some instances of auto-aiming and auto targeting to make the gaming experience smoother. The "game is about running around and blasting things," Carmack says, and so he didn't want players to be hampered by instances of pinpoint aiming.

To Carmack, Doom Classic is about moving around and shooting things; this makes Doom Resurrection's lack of movement and focus on aiming something of an anomaly for the series. Reviewers and many dedicated fans of the series saw Doom Resurrection as an aberration from the series' winning formula. Carmack admits that he "kept [Doom Resurrection] pretty tightly constrained" and used a lot of "smoke and mirrors" that improved performance. "We were under the belief that first-person controls wouldn't work. Tilt controls were playing to the platform's strengths," he says.