Well, it seems that despite selling over 4 million copies, the Guardians of the Galaxy game is considered a flop by Square Enix.
www.superherohype.com
That said, they are apparently planning on expanding sales to make up for the "loss", rather than simply writing it off as a failure.
Game publishers, if your game is selling literally millions of copies and is still considered "below expectations", I'm thinking the problem isn't with the game.

Square Enix Says Guardians of the Galaxy Sales Fell Below Expections
According to Square Enix, Marvel's Guardians of the Galaxy video game failed to live up to the company's sales expectations.
That said, they are apparently planning on expanding sales to make up for the "loss", rather than simply writing it off as a failure.
Game publishers, if your game is selling literally millions of copies and is still considered "below expectations", I'm thinking the problem isn't with the game.