Impeccable art direction and sound design. Exemplified by the boss fight with that worm machine, when you break its shield the music and sound effects stop and the camera focus on the blast that the enemy is about to take. These moments happen often throughout the game, and it shows a very strong direction where every element communicates perfectly with each other. From Soft has been killing it with its "cinematography" (I don't even know if there is an equivalent term for this in video-games) where lightning, composition, camera angles, environments are constructed/chosen with such care that makes everything so pretty, be it during gameplay and specially during cut-scenes. It's been happening for every game of theirs, and it's so nice to see this also translated very well in a sci-fi/high tech/industrial setting. 

Mechanically, the game creates a fantastic feeling of what I imagine would be to control a mech. In terms of game design, I appreciate the mission based structure, but I would have preferred a little bit more of exploration or more engaging normal enemies (maybe in a structure more similar to DMC or Bayonetta with small arenas where you fight a group of enemies). I think this would also have benefited NG+ and NG++ by mixing stronger/late-game enemies in earlier mission. Despite this, NG+ and NG++ are a step up from their previous games with different paths and added mission (and with its meta-commentary of you as the player knowing the story, and the game knowing that you know the story), which hopefully continue in their future games.