Call of Duty: Modern Warfare 2

Summary pulled directly from Steam - Some text may only be applicable to Steam platform

The most-anticipated game of the year and the sequel to the best-selling first-person action game of all time, Modern Warfare 2 continues the gripping and heart-racing action as players face off against a new threat dedicated to bringing the world to the brink of collapse.
Call of Duty®: Modern Warfare 2 features for the first time in video games, the musical soundtrack of legendary Academy Award®, Golden Globe® Award, Grammy® Award and Tony winning composer Hans Zimmer. The title picks up immediately following the historic events of Call of Duty® 4: Modern Warfare®, the blockbuster title that earned worldwide critical acclaim, including:

"Most Played Online Video Game" in history, 2009 Guinness World Records
More than 50 Game of the Year awards, including the Console Game of the Year and Overall Game of the Year, 2007, from the Academy of Interactive Arts & Sciences®

SPECIAL OPS CO-OPERATIVE

An entirely new gameplay mode which supports 2-player co-operative play online that is unique from the single player story campaign.

Special Ops pits players into a gauntlet of time-trial and objective-based missions.
Rank-up as players unlock new Special Ops missions, each more difficult.
Missions include highlights from the single player campaign, fan favorites from Call of Duty 4: Modern Warfare and all new, exclusive missions.

MULTIPLAYER REINVENTED

Setting a new bar for online multiplayer, Modern Warfare 2 multiplayer delivers new capabilities, customization, gamestates and modes, including:
Create-a-Class Evolved

Secondary Weapons - Machine Pistols, Shotguns, Handguns, Launchers
Riot Shields
Equipment - Throwing Knives, Blast Shield, Tactical Insertion
Perk Upgrades
Bling (Dual Attachments)

Customizable Killstreaks - AC130, Sentry Gun, Predator Missile, Counter-UAV, Care Package
Accolades (Post match reports)