Just 100%'ed.
Man, what a fantastic journey that was. Definitely my favourite 3D Mario game and probably the second best game I played this year (first is BOTW - kind of impossible to beat that one).
I was very underwhelmed initially, especially prior to starting the post end game content. I was even considering putting it aside, as in my eyes it was more or less a game that deserved a 7/10. Post game though skyrocketed my experience. The game totally builds up as you play and you get connected with characters, situations, the soundtrack, and the worlds. Also, once you get hold of Mario's moveset and become competent at combining the different was of navigating the environment, the fun and satisfaction you get by exploring the kingdoms changes completely. Initially, I used followed the predefined routes for reaching a particular point in the map, however when I was fully accustomed with the moveset I could find shortcuts and intuitive ways of reaching my destination. The stellar koopa races helped in that too.
I also enjoyed the climax of the journey. I left the very last challenge till I acquired all the moons, so I was totally immersed in what Nintendo tried to do with it.
Excellent game, looking forward to any additional content they release.