The Hogwarts castle is amazing. It's just like it is from the movies and you're free to move around it and explore the hidden rooms etc. They also have all 4 seasons in the game, and day and night cycles so you get to see the castle and landscape change.
If you're a Harry Potter fan, honestly it's worth the price just for exploring Hogwarts. I was amazed.
I enjoyed the combat in the game, although it wouldn't have hurt to add in a few more enemies. You learn most of the spells from the movies
You can upgrade your gear by gathering animals and collecting supplies from them, but it honestly felt a little pointless to do so because you're always discovering better gear elsewhere anyway.
I really liked a few of the side stories, especially the story with Sebastian, however the main story felt a little like the weird parts from Assassin's Creed. A lot of the mission locations didn't feel like they belonged in the harry Potter world, and the main story didn't have many surprises.
Overall, good game. Wish the story was a bit better and maybe the ability to make some impactful decisions.