So is this game overrated, or like..good?
Good. Real good. First good CoD since CoD 4. Finally, another CoD game that doesn't try to take itself super seriously. All of it is fun. Singleplayer, multiplayer, zombies. I'm playing a game about KILL ALL OF THE PEOPLE, not a game about SHOOT THE THINGS and also war and terrorism and death are bad and should be taken seriously and stopped and BATHTUB, TANGO TO THE RIGHT! The multiplayer is pretty much the same as it has always been in the recent games, but with some new and interesting ideas and nonexistant guns to check out. Zombies has been executed very well yet again with new, original maps, new characters, the Tranzit bus route mode and the 4v4 team gamemode (which isn't what I expected but is still very nice). As for Nuketown zombies, I haven't been able to play it because it's not available to all players yet.
TL;DR it's a game about shooting things in the future that you should definitely look at.