You asked why Half-Life's ending worked while Mass Effects did not. You did not ask whether or not Mass Effect can be considered an open world game. As such, it looks a bit like you're heading down rabbit trails, comrade.Originally Posted by Psyren
On the one hand, the only reason I'm interested is to see what kind of discussion it spawns, as the ending blunts any chance of real character development or really any plot relevance this might have. So probably some sort of BC hybrid.
On the other hand, I'm quite eager to see if BioWare can pull a Mask of the Betrayer and make up for the game proper by sheer force of good writing. Probably not, but as I am not currently a psychic of any sort I'll just have to wait and see with the rest of you.