Mass Effect 3 doesnt change much in terms of gameplay
Online streaming service Gaikai has snagged Mass Effect 3 as an online demo, meaning that anyone with an up-to-date computer can give it a go, as long as their net connection's up to snuff.
As with other game demos on the site, such as Rayman Origins, FIFA Soccer 12 and The Witcher 2, the fanciness of each game's graphics isn't dictated by players' computers but primarily by the sturdiness of their broadband line.
Where Gaikai works with publishers and retailers to bring flashy game demos to consumers, the rather similar OnLive is set on streaming full games to paying customers.
Mass Effect 3 on Gaikai: http://www.gaikai.com/games/mass-effect-3-gaikai