I cannot stress enough how much of a broken mess this game is. I'll breakdown my experience of each mode.
Campaign - The story of the campaign was great. However, it is frustrating getting immersed in the story and suddenly being greeted with a 'Fatal Error' message or some other crash error. Without the errors the campaign is a solid 4/5.
Multiplayer - This game mode is a hot mess. Lag, countless bugs, skill based matchmaking, constant crashes and connection errors. The crashes and other issues got so bad that I could not play the game anymore (I will get to that and my experience with support at the end), without being greeted with a crash error after seconds of opening or starting the game. The limited number of maps get boring real fast. Guns level slow. Skill based match making causes EVERYONE to have a 1.0 K/D ratio.
Zombies - A promising game mode that I had fun with for a bit before I couldn't play the game anymore. Gameplay did get a bit repetitive for me but long time zombies fans will love it.
My game got to the point where I couldn't play it anymore. I tried everything to try and fix it but nothing worked unfortunately. So I had to contact Activision and Blizzard support to try and fix my game or get some kind of compensation/refund. Activision's support was non-existent and no help whatsoever. Blizzard support just responded to my message with a link to Activision support and an apology message. After sending back a message politely stating that I had tried everything Activision said and fixes other people had posted online, and that I wanted to contact someone else or obtain a refund/compensation. They just responded politely telling me to go f myself and they couldn't do anything for me.