Microsoft announced that Halo 2 for Vista will not be shipping out today. Instead Halo 2 will ship to retailers on May 22 and gamers will be able to buy the title shortly afterwards. The reason for the slightly delay is for the developers to make improvements to the install experience and address “other technical issues.” Halo 2 for Vista has achievements to unlock that add points to your Gamerscore. You get 50 points for beating the game in legendary difficulty and you can earn 20 points for killing someone who has beaten the game in legendary. That’s a creative achievement system, which is bound to make hardcore players in game targets.