You also have to keep in mind that in some games a good UX may not be desired. While I believe an RPG's UX should be good (messing around with menus and inventory shouldn't be a chore), see the classic Resident Evil games.
One of the goals of the games is to evoke an atmosphere of uncertainty, fear and powerlessness. See how the health indicator is not a concrete value (75% life, for example) but an approximation (yellow life. You may know yellow means it's in [30-70]%, but you don't know the exact value.) This helps achieve the desired emotion while being, according to the traditional UI principles, a bad UI. It's not transparent enough for the user.
I consider the game's controls to be part of the UI. It's by using the controller and how the character moves the you interact with the game. MAny people dislike the RE's "tank-controls"[1], but I find it was a conscious and deliberate choice by the game designers to adopt this type of control. It's harder to control the character but help in achieving the desired emotions.
So, to answer you question... I don't know. But it's harder to evaluate game's UX's because it can't be evaluated in the same way we evaluate traditional UX's. Sometimes, in games, it's good to have bad UX's.