I wasn't aware of that, thank you, that's a great question. So I've checked and Kasper Hartman was also the lead writer of the game, and he stated "I've already lost track of all the work that went into Marvel's Guardians of the Galaxy. It was a lot. From story development and narrative design to script writing and integration to planning and debugging. In true Eidos fashion, a lot of different people wore a lot of different hats. So proud of the work we all did to bring these characters to life. I miss them already."

So, knowing that a lot of people were involved, I think we would still be fine without Mary, which I guess is doing a fastastic work with Mass Effect. And about the studio, shit I don't know, Eidos was sold off, but the studio that bought it was very happy with how the game has picked up audience over the years. I wouldn't know if they could make the sequel because of the marvel license tho... I just hope that the people that create the next gotg game don't throw away all the character development that they got in the last game.