Define broken.
I am enjoying playing through the campaign. My biggest complaint is the issues associated with always-online gameplay (see button delay bug).
If I were just playing offline, that would make it way better.
I enjoyed the campaign as well! I absolutely enjoyed the story. The visuals are great, the sound is great, I like this game. But there are issues with it and I don't like what the devs are doing to slow us players down either. I hate all the nerfs. It seems like they are doing their best to make the game less fun. That said, I am still playing each day. I keep hoping they fix the current issues and reverse some of the nerfs.
Some things that are broken: (this list is most likely bigger if you talk to others.)
Game crashes for many people. It's pretty bad and pretty random. My buddy crashes on a regular basis and when in the middle of a big battle or just before completing a quest, then to just have it crash...its rage time for him.
Broken skills. (skills that either are broken or don't do what they are supposed to.)
Resistance system isn't working
Enemies can target you and hit you from off screen
some quests and dungeons that are bugged and can't be completed. Bosses that die but don't despawn and just stand there not allowing us to finish dungeon.
Enemies being able to CC you back to back to back to back, making it impossible to survive. You might be able to get out of two or three CC attempts but as they continue to CC, you are pretty much screwed.
I'm at work right now so this list is just what I can think of at the moment.
Keep in mind, I have enjoyed this game but I expect more from a dev team selling a game for $69.99. They need to do better and I hope they do.