For example, major changes to the art style are something that would obviously generate a lot of negativity among fans, no matter what direction the game is taken in. The new style of “Diablo 3” was so controversial that Blizzard had little choice but to revise it.
In addition, changes related to the monetization of the game should always be communicated properly to the community. This is a sensitive topic for many, and it’s something Blizzard need to be very careful about as is evident by the way this game was received when it first came out.
On the other hand, the studio got plenty of things right too. The balance of the game was noticeably improved, especially when it comes to making it friendlier towards new players. This has been a bit of an issue for the game in its previous incarnations, especially “Diablo 1” which was not exactly welcoming to newbies.
The studio can definitely learn a lot from the way this game turned out, and if they put that knowledge to good use, we could see an amazing sequel sometime in the future.