Halo 2 is a first-person shooter, the sequel to Halo: Combat Evolved. It was developed by Bungie Studios in 2004 and became the best-selling first-generation Xbox game. It received Best Console game and Best Sound Design from the Interactive Achievement Awards and a number of other prestigious prizes.
The actions take place in the 26th century, when a conflict between the human United Nations Space Command and Covenant, the union of alien races, occurs. A player can assume the roles of human Master Chief and alien Arbiter. Throughout the game, players are protected by damage-absorbing shields, which restore when not taking fire, and are free to use both human and alien weapons. A player can use two weapons simultaneously as each of them has its pluses and minuses. The armor of Master Chief is equipped with a flashlight while the one of Arbiter has a temporary rechargeable form of active camouflage. Moreover, in this game, it's allowed to use enemy's vehicles, which are near the character, and travel in them after getting rid of the driver.
Halo 2 has a "Campaign" mode, in which both single-player and multiplayer options are possible. The mode has 4 levels of difficulty: Easy, Normal, Heroic and Legendary. As a player proceeds, the number, rank, health, damage and accuracy of enemies increase. The game also has some hidden content like messages, hidden objects and weapons. The most widespread hidden objects are skulls, hidden at secret places. Each skull may influence the game differently and, in addition, their effects may be combined.