The puzzles are the worst of it. Some are optional and fine to walk away from. Others sit directly in the main story and will stop you dead, because they introduce mechanics the game has not explained and offer no hints of any kind. During the review period Pearl Abyss set up a Discord so that reviewers could share puzzle solutions with each other. That is an extraordinary thing to need to do, and it means you should expect to look up a guide at some point.
Bosses are wildly inconsistent. The good ones are excellent — long, tactical, properly staged, and a real test of whether your gear investment paid off. The bad ones are simply too aggressive to react to, and dying to one is expensive: fast travel points are sparse, you often respawn a long way back, and you may have to redo a puzzle you already solved to get another attempt. Between-phase cutscenes can be sped up but not skipped. Some of the early bosses are harder than later ones, so the difficulty curve wanders.
Then there are the bugs. Individually most are small. Collectively they are constant, and they get noticeably worse in the back half — including quest bugs that can block progression. The day one patch cleared out a lot and Pearl Abyss has been unusually quick to respond, but the honest read is that this game needed longer in development.
And the story never really arrives. There are strong moments, particularly the quieter ones, and the sense of scale between warring factions is genuinely Game of Thrones-ish. But Cliff is not a character you will think about afterwards, the flashback-helmet device used to deliver backstory is a poor substitute for actual cutscenes, and we finished the game feeling attached to the world and to nobody in it. The world is the main character. That is a real limitation, and it is also, for this particular game, survivable.