Depending on who you ask, Marvel's Avengers is either a great game that was miscast as a live-service title or a bad game that underwhelmed. Both praises are valid. After all, Marvel's Avengers has a solid single-player campaign and is good to play for the first dozen or so hours. The key issue with the game is that it tries to get you to stay once you're finished with the single-player campaign and fails to give you a reason to do so. At the same time, it's a game based on arguably the most popular superhero franchise right now - it should have sold more than it did.
Square Enix views Marvel's Avengers as a disappointment. However, regardless of what your stand on the game is, Crystal Dynamics deserves a lot of props. The studio has continued to work hard on a game that continues to be the subject of heavy criticism. Case in point, Spider-Man is finally coming to Marvel's Avengers.