Bungie and Microsoft created an even more successful sequel to Halo: Combat Evolved (2001) known as simply Halo 2 (2004).
Master Chief (Steve Downes) was part of Cairo Station and learned that the Covenant just invaded Earth, specifically Africa. As he fended off the invasion, he learned that there is another Halo in the galaxy.
The multiplayer was well-known for having reliable gameplay methods and a variety of maps to play in.
The game made an equally great impact as its 2001 predecessor due to the improved gameplay and unexpected twists in the single-player/co-op campaign. This gave Bungie and Microsoft to finish the initial trilogy on the Xbox 360 with Halo 3 (2007).
Halo 2 is a great sequel to a great video game and an important icon of 2004.