User blog comment:Deathmanstratos/Some Call of Duty: Advanced Warfare singleplayer background information revealed/@comment-402843-20140510041529/@comment-1263839-20140511005513

Well it depends on how the developers change things. Bungie clearly wanted to change Halo ever so slightly with every game while Infinity Ward and Treyarch are fine with having the gameplay stay mostly the same but at the same time want to add in things you can do with this gameplay (hence all the gadgets you use for a mission or two but never again).