Absolutely phenomenal. Everything from the gameplay, to the environments, to the excellent story and characters, to the music, to the amount of content, is just perfect. I think there are games that are objectively better, but this is (for now) my favorite game I have ever played. It's an experience I hope everyone can have one day. Play this game if you haven't already, it's amazing.

EDIT: I like Xenoblade 2 the same amount, and Xenoblade 3 even more