Well, it is getting to be the same thing over and over again. The campaign is still a shooting gallery and the multiplayer is still a twitchshooter with arbitrary ranks and an in-game reward system (killstreaks). Multiplayer is still mostly about sprinting around the map and making sure you get the first shot off. The levels are kept small, but kind of have to be considering the play style. There aren't any other gameplay mechanics to break up the game like Battlefield and Halos vehicles, or TF2s unique classes, or Quakes weapons and pickup-based gameplay. Anything they add has to be in the confines of what they've already created and theres just not a lot of room. I can't imagine CoD as anything but a twitch shooting game of tag.

The problem is there isn't much to change if they want to keep it similar to previous games, and the stuff they can change they're afraid to touch. The biggest alteration in the series was from 3 to 4 and it worked out well. If they kept innovating like that, there wouldn't be as much of an issue. If they went from MW3 mechanics straight to BO3 mechanics, it may turn off some fans but people would respect it more. As of late, they've just slowly changed into something different. A new mechanic here and there to change it up just enough for most people, but not enough to endanger their sales. What ends up happening is from AW up to IW, the game is already partially stale.

I'm not a CoD hater by any means, I used to buy every game and every DLC for it up until AW. I just don't like twitch shooters anymore. But CoD is still the best at it, so if I ever do come back to the genre I'll still pick up the newest iteration.