I do not understand why this game is getting so much hate. Trying to innovate is good and asking for something new and then hating it because it is too different is something that the COD community needs to stop. From the looks of it, people are just complaining about servers and their own poor internet, but this is my genuine opinion of the game.
The campaign is phenomenal. The only complaint I've heard is that it's too short, which I would completely disagree with. It took me a little over 6 hours to complete and every bit was fun. Really complex, reminds me of bo1 with the multiple decisions like bo2. And the soundtrack is top tier. Really well done.
The multiplayer is really nice and smooth. Definitely an improvement from bo4 and bo3. I did not get modern warfare, and I understand that that is a huge point that people bring up (it's just a rehash). But from someone who is new to this type of call of duty, it is really fun and flows well.
However, it does have its problems, most notably the weapon level and camo systems. I do not understand at all why a weapon needs over 20 levels. There are too many attachments that they can combine or simply get rid of. Also, I do not like how much I have to do for a camo. I get it is to show off talent and hard work, but the old fashioned way showed it just as much. Most of all though, the mp5 is annoying and should just be deleted from the game. However, these are small things and does not take away from the gameplay in a drastic way.
Lastly, I really like zombies. I have played zombies for years and years now and I really love what they have done to innovate. I can understand people who have come back wanting classic zombies, especially after the complexity of bo3 and bo4. However, no matter what anyone says, they need to innovate to keep it interesting and they did that so well. They took the challenge of easter eggs, puzzles, and buildables and simply put it into gameplay with tiers, field upgrades, and the PAP system. I get people who don't like it because it's not classic, but from an innovative standpoint, they did everything right.