In the original M2033 there were at first this options: easy, normal, hardcore.. then they have released a DLC in which they added Ranger Normal - harder than hardcore, but still visible HUD, UI, etc.. and Ranger Hardcore - the same as Ranger Normal, but the HUD & UI are gone (for the most time, i don't know if the whole time).. and now in Redux, you have Normal, Hardcore, Ranger Normal, Ranger Hardcore & you have this modes now to choice: Survival (guns are reloading slower, AI is smarter, fewer filters, ammo, etc = style of the original M2033) and Spartan (faster reloading times, more filters, more ammo, etc.. = style of Last Light)