All of the Call Of Duty games feature a familiar type of gameplay... but the fact is that the creators of the games have gotten this down to a science and have repeatedly(!) created a very immersive gameplay experience. Because every level and game are slightly different, and have their own perks, COD has not devolved into a mindless rehash, but has rather brought an opportunity to purchase a title that has a good chance of being as enjoyable as the last, with a non-existent learning curve.