Mass Effect is a new RPG from BioWare who developed the critically acclaimed Star Wars: Knights of Old Republic games, and Jade Empire. The game takes place in a sci-fi world where space exploration is common and robots, aliens and humans comingle. The action is split into three main modes: conversations with other characters, exploration around the galaxy, and combat.
BioWare focuses a lot of energy on the conversation side of the game introducing a new form of dialog progression that moves away from requiring copious amounts of text and instead is more emotion base. Every character is fully voiced, and the player simply chooses a general kind of reaction with the actors fleshing out the reaction with the proper animations and voice.
Exploration is further divided into two stages, one is the galactic map where you can choose to pilot your ship, the Normandy, to hundreds of different planets. Once a planet is selected you move into the second form of exploration which involves a combination of driving and walking around on the planet's surface.
Combat is a hybrid between real-time action, and turn-based strategy. The flow of the combat is real time where you control a single character and aim their shots, perform attacks and execute abilities. At any time you can pause the action to take a more strategic approach and queue up commands to the entire party.
Being an RPG, character development and stat progression plays a large part with all of the characters able to gain new abilities, weapons and armor. All the weapons and armor you equip are visible in real-time during the game.