DOOM has always been about simplicity. The simple joy of running around and shooting demons without having to worry about looting or crafting or talking to anyone so you can complete multi-layered objectives. But while the new DOOM Eternal (Xbox One, PlayStation 4, PC, Switch, Stadia) continues this approach, the good people at iD Software have added some interesting new mechanics to this sci-fi first-person shooter, and this sequel is all the better for it.