Grand Theft Auto: Chinatown Wars was meant to be a massive hit. It goes back (somewhat) to the old days of Grand Theft Auto, having a top-down view (albeit isometric rather than true top-down) rather than a Third Person View. It had all these features, great controls, and yet it hasn't sold so well so far. In the first two weeks, it only sold 90,000 units in the US, a figure paled by the release of Pokémon Platinum, a recent title with similar fanfare, with over 800,000 in the first nine days, mathematically almost 14 times more successful in the same period of nine days.
There are reasons for this.