Here's the fact sheet for Bioware's Mass Effect:

"Mass Effect" is a science fiction action-RPG created by BioWare Corp., the commercially and critically acclaimed RPG developer of "Jade Empire," "Star Wars: Knights of the Old Republic," "Neverwinter Nights," and the "Baldur's Gate" series. "Mass Effect" will deliver an immersive story driven gameplay experience with stunning visual fidelity. Published by Microsoft Game Studios, "Mass Effect" will be exclusively for the Xbox 360 video game system.

As the first human Specter - sworn defenders of galactic peace - your mission is to halt the advancing armies of a legendary agent gone rogue. But as you lead your elite team across hostile alien worlds, you will discover the true threat is far greater than anyone imagined.

Key Features:

• Immersive RPG: Determine the fate of mankind as you lead an elite tactical strike force as an epic galaxy-wide conflict unfolds. "Mass Effect" will take the player into new depths of an action-roleplaying game, with choice-based gameplay.
• Rich and engaging storyline. While defending galactic peace and earning a position of respect for humanity in the community, gamers will discover that a greater conflict between organic life and artificial intelligence exists. Players' decisions and actions will serve to shape the destiny of all life in the galaxy as you become absorbed in the story that is "Mass Effect," the first game in an epic trilogy from BioWare. They will become the center of an engrossing story as they battle against alien life forms to save the galaxy from threatening armies.
• Player controls the ultimate fate of the galaxy: The player's decisions and actions will serve to shape the destiny of all life in the galaxy, while raising humanity to the pinnacle of galactic civilization via noble means or via tyranny.
• Real-time squad based combat: "Mass Effect" employs a real-time, squad based, tactical combat system. Players will be immersed in intense, challenging and exciting combat.
• Explore uncharted worlds: In addition to the main story arc of the game, players will be able to visit a large number of uncharted, unexplored planets which are not directly tied to the main story. At any time during the campaign, a player can choose to explore one of these planets in an all-terrain rover in order to discover new alien life, resources, ruined civilizations and powerful technologies.
• Digital actors: "Mass Effect" features a huge cast of in-engine digital actors that you will encounter as NPCs, enemies or as party members. Each will have life-like facial and body movements, and an advanced dialogue system will give them engaging personalities.
• Character customization. Players will be able to choose from a variety of stunning, photo-realistic character appearances at the start of the game, and throughout the game can increase various statistics which will have an impact on their performance during gameplay. Equipment, weapons and armor that are acquired during the course of the story will change the appearance of the characters.
• Next-generation gaming defined. "Mass Effect" takes advantage of Xbox 360's hardware providing gamers with exciting new experiences, including photo-realistic, high definition graphics on an epic scale. As the future of gaming goes online, Xbox360 live features, including premium downloadable content and recognition of achievement will be available via the Xbox Live service.