From Wikipedia:
Halo 3 is a first-person shooter video game developed by Bungie for the Xbox 360 console. The third installment in the Halo franchise, the game concludes the story arc begun in Halo: Combat Evolved and continued in Halo 2. The game was released on September 25, 2007 in Australia, Brazil, India, New Zealand, North America, and Singapore; September 26, 2007 in Europe; and September 27, 2007 in Japan. Learn about Halo 3
