Just beat today. 100% Items. 14.5 hours (over 20 total on Switch... guess I died A LOT). So much fun. I can now safely say, this is my game of the year.
My 2nd ever 2D Metroid after Samus Returns. Such a phenomenal experience.
I will not be doing Hard mode though lol. Normal was hard enough for this guy.
Only negative things I can say are:
I wish the loading times between areas were shorter
I wish the music was more memorable
Other than that, I've loved every second of this game. As a relatively new fan of this series, please try/buy this game. I'm very glad I didn't have to wait 19 years and hope it doesn't take that long this time :P.