Popular game title Call of Duty: Black Ops has achieved a milestone by crossing the $1 billion in sales from around the world in less than two months of its launch, game maker Activision said on Thursday.

The figure is only internally calculated but shows that the game has been sold faster than any game for console yet. Call of Duty: Black Ops had earned $360 million in just one day of its availability in worldwide revenues, which was more than its earlier version, Call of Duty: Modern Warfare 2, which generated $310 million on its launch day. The earlier version took two months to reach the $1 billion worldwide sales figure.

In Black Ops, the players take the role of Special Forces agents in places like Russia and Vietnam. It games takes the player to action sequences during the 1960s and the cold war. The game opens to an aggressive interrogation, leading to playable flashbacks from the titular covert missions.

Black Ops also features historical events like the Bay of Pigs incident and Kennedy's assassination and is bit longer than Modern Warfare. The controls remain similar to that of the earlier version with sharp movements and responsive controls. The weapons have received an upgrade where reload speed, ballistic power and accuracy are balanced to make sure that it does not offer an unfair advantage in multiplayer.

Activision has said that gamers have played the game for more than 600 million hours online. Microsoft, which furnished Xbox Live figures to Activision, has said that the average player typically plays Black Ops online more than once a day for over one hour at a time.