Dan Houser – former writer and creative director of the Grand Theft Auto series – says GTA 4 was so tonally different from what came before because Rockstar Games felt that doing the same old thing risked obsolescence.
GTA was riding high going into the Xbox 360 and PS3 era, with the trilogy of GTA 3, Vice City, and San Andreas all releasing to mass acclaim, selling millions, and becoming some of the most influential and beloved games of the era. San Andreas, in particular, felt like the natural culmination of the style established in GTA 3, so the idea of that continuing on more powerful hardware was certainly exciting. However, GTA 4 turned out to be a somber story, with a more realistic world and a far darker tone overall.
Speaking to IGN, Houser explains, "There was a belief that San Andreas had taken that kind of 'pop' energy as far as it could go." Given that San Andreas was so "massive" and "successful," Houser notes "that for GTA to stay relevant it had to reinvent itself."
While GTA 4 isn't quite as popular as the two games that surround it, Houser points out "it felt cohesive. The game, the art direction, the moody lighting, the nature of the missions, they all felt tonally consistent."
He notes that with the darker take on the series "we found a level of tonal consistency that we'd not had in the previous games," even if that could be seen as a risk given the success of the PS2 games.
Houser recalls that with Rockstar, "I think there was more [of] a perception that the risk was the opposite," he explains. "The risk was if you don't reinvent yourselves and don't do something new and fresh, you're going to become obsolete." GTA 5 then did become a bit more lighthearted and silly compared to 4 and proved to be a juggernaut both in sales and popularity, but Rockstar's more somber tone in hindsight feels somewhat like a precursor to the Red Dead Redemption games, so really I think both takes were for the best.
