In an interview with OXM, Mass Effect 3 lead writer Mac Walters revealed that a series of side missions taking place on the Citadel were removed from Mass Effect 2 but will appear in next year's sequel.
"There was a Mass Effect 2 plot that was a kind of a callback to the first Mass Effect that was going to be on the Citadel, and we cut it," Walters said. "But now it's made a resurrection in Mass Effect 3, so I'm happy, but I can't say what it is.
"That's the nice thing about trilogies, sometimes you get a second chance."
In addition to its story, Mass Effect 3 will feature the co-operative Galaxy at War multiplayer mode. Galaxy at War will be impacted by the choices made in previous Mass Effect games and will influence the third game's story.
Mass Effect 3 will be available on Xbox 360, PlayStation 3 and PC from March 6 in the US and March 9 in Europe.
> Read our hands-on multiplayer preview of Mass Effect 3
> Mass Effect 3 campaign to feature action, story, RPG modes
> Mass Effect 3 Collector's Edition adds bonus character, robotic dog