Sure, it has a very identifiable look, aesthetic and environment. No doubt, but so did Fallout 3. And that was released ages ago. That was all neat, but the part you play, the GAME, was old hat. If they really took 6 years to develop the world, that is just too long, especially when similar games have done similar things with less time, while at the same time building new gameplay systems to complement them.
I will say this Ken Levine is a talented writer and world builder, but they need to fire the engine/programming staff at Irrational. They are slow as hell and the end product is not all that impressive. If it took 6 years to develop the world and the look and the story, hire some goddamn system programmers to develop a game with 6 years of innovation in it as well.