Halo 3: ODST was a side project developed by the Bungie community to give more insight on soldiers under the UNSC. These Orbital Drop Shock Troopers had a small part in Halo 2, but that was where their involvement ended. This game gives players a chance to be an ODST instead of a supersoldier, like the Master Chief in other Halo games. By going from being a small endeavor to a full-sized game, ODST was the top selling game for Xbox 360 on a worldwide scale.
The setting of this game is in the 26th century, where humans and aliens are still at war. The United Nations Space Command is in charge of the humans and their alien enemies are call the Covenant. The Rookie is the main player and he has a squad of 5 teammates to assist with missions. The entire team enters into their HEVs, or Human Entry Vehicles, and prepare to drop through the atmosphere. They are to head to the ship belonging to the Covenant, but a teammate had changed the trajectory on the HEVs.
This change caused the alien ship to jump into hyperspace, triggering a shock wave that hits the group of HEVs. The Rookie ends up in a collision course with another HEV, due to this shock wave.
The collisions knocks him unconscious for six hours. Once the Rookie awakens, he finds that his entire squad is missing. The game evolves from the need to find the missing squad and the adventures that occur along the way.
As the Rookie finds articles belonging to missing soldiers from his group, a flashback occurs. This moment allows the player to see what the other soldier went through and enables him/her to be in control of that teammate for a while.
Along the way, there are many shootings, rescues of lost teammates, plenty of missions, and even a couple of new characters are thrown into the mix. Other Halo games are played as a supersoldier, but being a UNSC soldier is just as adventurous.
When creating this game, the composer of the musical score decided to not use the traditional Halo themes. Instead, he moved more towards a softer jazz sound, giving a whole new feel to the atmosphere. There were many positive reviews regarding this formation of the game, as well as to how the overall story was set up. Halo 3: ODST started off small but grew into an amazing adventure for Halo followers all over the world.GameFly™ - Official Site