How did I not know that Call of Duty: Modern Warfare 3 Zombies was this much fun?

It's that time of year again where a new Call of Duty is on the horizon and the existing game has been played so much that older titles in the franchise get wheeled out for a dose of nostalgia and a change of pace. With an Xbox Game Pass subscription, that's even easier. In my case, I've been checking out a couple of previous Call of Duty games I...