So I finally got around to completing this game. It's Assassins Creed: Mordor Edition. Plainly there was very little in the way of game mechanics that wasn't lifted from any AC game from 2 onward. For those that have no interest in playing the game but are interested as to what the story entails I'll put that in a spoiler.
The game plays well, the combat flows nicely with animations hitting the intended target the vast majority of the time and sounding meaty when doing so. It sounds brilliant, the voice acting is some of the best I've heard and the choreography for the cinematics is fantastic. Its AC but it is definitely better than AC.
Celebrimbor the smith defied Sauron even as he helped forge the ring of power. Cel stole the ring just as it was finished and led and army of Orcs against Sauron using some sort of power that ins't really explained all that well. Anyway, he pretty much smashes Sauron and is just about to kill him or whatever you do to an evil Ainur when the ring slips from his finger and lands on Saurons. 10 points for guessing what happens next. After Cel is defeated, he's tied up and is forced to participate in a ritual whereby Sauron kills his wife and child and it locks Cels spirit in Mordor.
FF to when the game is set: You play as Talion, a Gondorian Ranger, one of the many atop the black gate. Orcs led by the Hand of Sauron (Saurons black Numenorian guards) take the black gate and perform the same ritual on Talion and his family. Talions body is still pretty much solid though so the wraith of Cel takes it. Talion is still in there so the two sort of live and act together. Que Orc killing rampage and revenge tale against the Hand. Its a decent story, fits well enough into LotR lore.