The Killer APP for the Xbox can be most readily described as one of the greatest games of all time.
Halo: Combat Evolved was released in 2001 with the Xbox. It was the Killer APP for the Xbox and, to this day, it is regarded as an astounding achievement. Halo had great graphics, audio, a great storyline, and most importantly, unbelievable gameplay.
Even five years after its release, I still think Halo has decent graphics. Five years ago, they were phenomenal. I can't say much about them now since today Halo's graphics are surpassed by practically every game released, but in 2001, they were really good. They weren't perfect, but they were good enough that gamers were wowed at times by the things they saw onscreen.
The audio was one of the best things about this game, even though many people don't think it's important. The Halo soundtrack is probably one of the greatest ones ever found in a game. When the song everyone associates with Halo came on during that great fight in the snow and the electric guitar pounded out chords, you just felt compelled to kick Covenant ass. The voice acting was also really good, especially by Cortana, who accompanied Master Chief through most of the game. The quality of the voice acting really adds to the cinematic experience.
Finally, there's the gameplay - the most important aspect of any game. Halo didn't do anything too remarkable with the first person shooter genre, but it took all of the familiar elements, trashed the bad ones and tuned the good ones. The result was an effect that I still haven't been able to label. In fact, I'm still not quite sure what it is about Halo that's so great. My theory is that the elements of the FPS were simply mixed together in the perfect manner to create one hell of a shooter.
Halo's single player campaign was one of the best in gaming history. Gamers took control of the Master Chief, a genetically modified superhuman called a Spartan. The Master Chief was a man of few words with incredible strength and skill with weapons. At the start of the game, the Master Chief is taken out of cryogenic sleep in order to aid the humans in their war against the Covenant, a group of alien races who have joined together to eliminate the humans. The Master Chief is awoken on a huge spaceship called the Pillar of Autumn which is almost immediately attacked by a bunch of Covenant capital ships which unload their soldiers on the Autumn. The Master Chief picks up Cortana and a few allies and then leaves the ship on an escape pod. The escape pod rockets the passengers onto a huge ring orbiting through space. The outside of the ring has a mechanical appearance, but the inside of the ring is a whole world. The ring is called Halo. On Halo, Master Chief must fight off the Covenant and a few other enemies hellbent on destroying humanity.
The single player campaign is lengthy and filled with action and adventure. It is probable one of the best single player experiences I've ever had.
Halo also had an awesome multiplayer aspect. The multiplayer was either local or on Xbox Live and had tons of modes including Deathmatch, Team DM, Capture the Flag, and more. It was tons of fun and provided for hours of entertainment.
Halo: Combat Evolved was the best game to come out on the Xbox and is certainly one of the greatest games of all time. It had a great single-player campaign and excellent multiplayer modes. It has gone down in history as one of the greatest games ever and I'm sure in ten years it will be rembered by gamers in the same way we remember Doom.