XC is a great game. Loved the characters, the music was the best of any game i've played, had an engaging story i wanted to find out more about and the world was breathtaking and interesting. I also loved the two world premise. The combat is deeper than you would think at first. I knew when Nintendo first showed the game at E3 almost 10 years ago, that it would be something special. I think back then it was called "World of Monado" or something, and very little was known, and it got very little attention.
Accept all sidequests you happen to encounter, don't go out of your way to accept or finish sidequests, and you'll notice you'll finish a lot of the sidequests you accepted with no effort. If you really feel a certain sidequest is interesting, knock yourself out, but don't do it if you don't feel like it.
Just try to move on with the main quest. It's what drives the game, the story, the world, the characters...
Now, XCX on the other hand, is a complete and utter turd. I really feel hustled buying this game and the special edition no less. I waited years for a follow up to XC but whatever XCX was, it sure wasn't that. Horrible music (the worst tracks are litterally the tracks you will hear roughly one thousand times), no story, no soul, bad characters... and the main quests are about as interesting as the sidequests from XC. It's a shame really, because this could have been great. Mechs (which turned out to be more tedious than going on foot), huge world with some great regions, nice graphics... I wish they would rerelease the game but this time, added an actual story/quest. So much work went into the world and creatures, it really is a shame. There was little sense of accomplishment, there was no real incentive to keep playing. I bailed somewhere in the third or fourth world. I think i had put in a good 40 to 50 hours and didn't enjoy any of it.