Mass Effect is a video game. Specifically, a role-playing, third-person shooter hybrid, affectionally called an action-adventure game.
While I have not played Mass Effect as I'm not a gamer I've followed the world a little bit after reading these other older Trek BBS threads:
Mass Effect this generation's Star trek article
Is Mass Effect the next Star Wars?
MASS EFFECT: Spiritual successor to Star Trek?
and of course even with the Halo
film stalled in development and the unsuccessful Doom
movie based on a similar videogame and there is an upcoming Aliens: Colonial Marines
game that looks amazing there is a 'Mass Effect' scifi videogame In Film development deal
It’s the product of the best parts of Star Trek, Star Wars, Battlestar Galactica and more with a protagonist who could be the love-child of Picard, Skywalker, and Starbuck. It’s one of the most important pieces of science fiction narrative of our generation. Mass Effect goes so far beyond other fictional universes in ways that you may not have yet realized.
As a vessel for an epic science fiction narrative, the medium of action-adventure game affords three immediate advantages – setting, casting, and emotional involvement.
from the popbioethics site is quite an article I've quoted from:
Is Mass Effect "The Most Important Science Fiction Universe of Our Generation"?
the Mass Effect universe is certainly built upon a lot of preexisting science-fiction (most notably Star Trek), it's pushed a lot of those ideas further and weirder.
I really like this from a review of the game that comes out next month
Mass Effect 3 continues along this path and gives the option to divide the game into three distinct modes: action mode removes dialogue choices, story mode features extremely easy combat and an emphasis on narrative, and role playing game (RPG) mode plays more like previous Mass Effect titles, mixing elements of the game’s previous two modes.
yes very epic. See the this Youtube link Mass Effect 3: Take Earth Back Cinematic Trailer
This mode : story mode
allows for casual people who are not gamers to get into the story and interested in the universe.