It wasn't just the art direction that was bland. The entire concept of sentient killer robots is incredibly tired and the gameplay, while solid, was very basic and typical of the genre. While Vanquish injected a much needed burst of energy with its sliding movement gimmick, BD played things very very conservatively. It felt too much like a Japanese dev trying desperately to appeal to the West more than a game driven by vision or fun ideas. The twists in the narrative were also very disappointing, [spoiler]with even the big bad US government making a grab for power at the end.[/spoiler]
I did very much enjoy Cain though. He was the best character by far.