I've watched the gameplay and I still don't understand why everyone is losing their shit over this...
It's not for everyone, but the game is GORGEOUS to look at and its tack sharp to play, it just *feels* good. Its mostly a boss rush with genuinely fun and interesting bosses that aren't just bullet sponges, set in the above mentioned BEAUTIFUL world. It has a well tuned difficulty curve for those who like that kind of thing.. Its tough, like, infuriatingly so, but you rarely feel like the game was unfair.. You usually just fucked up and could have played it better..
All in all the game has a unique look and feel, and under that, its just a really really good game.