Sony has confirmed that Killzone 2, Guerrilla Games' PS3 exclusive first person shooter, has sold at least 1 million units worldwide so far. The company pointed to the game as another example of an "only on PlayStation experience," and noted that it will "continue to drive incentive for hardware sales throughout the year."
Killzone 2 managed to sell over 600,000 units according to February and March NPD results, meaning it atleast managed to sell 400,000 units in Europe. The game has still not released in Japan, but first person shooters tend to do better in European and North American markets.
Some may look at the sales of this game and consider them disappointing, and they probably are, however PlayStation 3 titles have proven over and over again that they do not sell millions of units in the first few days. A good example of this is Uncharted: Drake's Fortune, which sold a ridiculously low amount of units (32,000) in North America in the first week. The game has now gone on to sell over 2.3 million units worlwide.