Set 200 years in the future in an epic universe, Mass Effect places gamers in a vast galactic community in danger of being conquered by a legendary agent gone rogue. A spectacular new vision from legendary developers BioWare, Mass Effect challenges players to lead a squad of freedom fighters as they struggle against threatening armies to restore peace in the land. Mass Effect is the first in a trilogy of games with an overarching story. 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.
Special Features:

Player controls the ultimate fate of the galaxy: The player’s decisions and actions 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

Mass Effect employs a real-time, squad based, tactical combat system

In addition to the main story arc of the game, players are able to visit a large number of uncharted, unexplored planets which are not directly tied to the main story

Players are able to choose from a variety of 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 change the appearance of the characters

Optimized controls designed specifically for the PC

Higher resolution PC visuals -- The world, characters and creatures of Mass Effect are more stunning than ever before. PC Gamers will be in awe of the incredible vistas, cities and landscapes found in the Mass Effect Universe.

Free Downloadable Content -- The "Bring Down the Sky" downloadable content is free for PC gamers to download. It includes 90 minutes of new gameplay, an original soundtrack, and a new uncharted world that introduces the deadly Batarian alien race.

Tactical HUD -- A new Tactical Heads-Up Display (HUD) allows players to access the Individual Squad Command, Biotics powers and Abilities and Weapons command interfaces all in one screen.

Individual Squad Control -- PC gamers will be able to control each of their squad mates via a simple to use interface.

Re-designed Mako controls -- Players can explore alien planets and engage in vehicular combat with an intuitive and fully camera independent control system for the Mako, their all-terrain vehicle.

Enhanced Inventory System - Makes it easier for players to equip and modify their weapons and armor.

New Decryption mini-game -- Fully redesigned, the team created a mini-game that reflects the shape and methodology of the Omni Decryption Tool used in the game.

New Save Features – Players can Auto Save with the touch of a key and Mass Effect for the PC also features an expanded number of Save slots.
System Requirements:

Windows Xp/Vista
Single Core: 2.4GHz or better / Multiple Cores 2.0 GHz or better
Xp: 1GB RAM
Vista: 2GB RAM
15GB HD
1x DVD-ROM
256MB Video Card support for Pixel Shader 3.0
DirectX 9.0c