As someone who tend to dislike most Metroidvania games I'm really impressed with the fact that this one is so superb considering that initially it wasn't even designed as one and this incarnation of it is the product of years of reworking the initial release as a free expansion. Incredible job.

It has everything I want in one of these. Good, thoughtful world design. Great pacing with areas that are only as big and populated by enemies as they need to be. Very meticulous encounter design and enemy placement, and just incredible (and plentiful) boss fights.

The fact that it's so pretty and the soundtrack so consistently beautiful adds a lot too.

It's worth mentioning that the game takes a lot after Souls too, but I think it's pretty successful at borrowing some of its elements. There's a meaningful leveling system with stat allocation that makes builds matter, varied weapon types and even classes, all with their distinctive features.

The writing is surprisingly good and poignant as well, but has the caveat that, for some reason, they decided to add a lot of humor to this expansion that, while funny in isolation, is really jarring in how terribly it clashes with the tone of the rest of the game. Feels straight up out of a different game altogether... But it's really worth ignoring for the interesting narrative and of course, the wonderful package the rest of the game is.