It's often expected that the best games of the year offer completely new experiences--things we've never seen before. But there is also great value in building upon what has come before; in taking common mechanics and ideas, and pushing them a little further. Each of the Xbox One nominees are notable for doing a little of both in some fashion. Dragon Age: Inquisition brought the BioWare RPG formula into a beautiful open world, whilst Metal Gear Solid V: Ground Zeroes did the same for its own solid stealth mechanics. Titanfall surged multiplayer vehicular combat forward with its man-versus-mech matchups. Far Cry 4 iterated on every aspect of its tropical predecessor to create a more cohesive sandbox sojourn. But it was Middle-earth: Shadow of Mordor that offered the most impressive take on the familiar-yet-fresh approach of the year.
To say that Shadow of Mordor consists merely of the combat from the Batman: Arkham series and the open world traversal of Assassin's Creed would be failing to see Mirkwood for the trees. Yes, Shadow of Mordor is a greatest hits-like collection of tried and tested open world action mechanics, but the manner in which they allow you to interact with the game's nemesis system at its core paints them in a whole new light. More than just a visual Uruk hierarchy of warlords, captains and their bodyguards, the nemesis system imbued those familiar action mechanics with a new kind of systemic consequence by giving those enemies unique properties and character traits. You needed to explore the full extent of your combat abilities, of your means of traversal, and of the environment's topography to exploit the Uruks' weaknesses and sunder Sauron's forces from within. Developer Monolith trusted in you to undertake such exploration yourself, resulting in highly personalised encounters with Uruk chieftains that would remember you, taunt you, and feel like active agents in a world where the balance of power was constantly shifting.
After playing Shadow of Mordor, it's hard to go back to third-person action games that don't leave as much room for player expression, and go to such lengths to tell player-driven stories. It is equal parts an accomplished refinement of what has come before, and a confident step forward into new and fascinating territory.