Following the hugely successful Halo: Combat Evolved, Halo 2 was released to an audience which highly anticipated the sequel’s release. The game gained 1.5 million pre-orders before its release, and it ended up earning $125 million in the first 24 hours of its release, which at the time was the greatest amount of money an IP had made in that time span (beating out Pirates of The Caribbean: Dead Man’s Chest).
Halo 2 expanded the Halo universe through a campaign mode that fleshed out much of the original’s storyline, but the main mark of its success was its online multiplayer component. Well into 2006, more than half a billion hours had been played online, and the game remained the most-played online game until Gears of War’s release. The entirety of Halo: Combat Evolved has the player spending their bullets on a Halo or on various spaceships belonging to the invading races of the Covenant. Halo 2 is a marked change in that most of the game sees Master Chief gunning down aliens on earth. Another huge change was that the game allowed the player to play as the Arbiter, a leader who becomes part of the Covenant resistance after he learns the plan of the Covenant leaders to eradicate all sentient life in the universe. In addition to new weapons, multiplayer maps, and locations, Halo 2 introduced dual-weilding, which allowed players to wield two 1-handed weapons in each hand. This was both maligned and enjoyed as some players felt the combinations of certain weapons was too powerful to overcome, while others simply enjoyed the combos. Bungie did eventually nerf (power down) some of the weapons, namely the Needler.
Halo 2 was the last title in the Halo series to be on the original XBOX, and it remains to be the most popular original XBOX game to have ever been released.