I wouldn't usually do this, as this is a book blog, but it's thanks to the Harry Potter books that I had the release date for this game in my calendar, and I've been playing it ever since, so I thought it might be worth a mention.
This is "Harry Potter: Hogwarts Mystery"
In the game you create your character, and then get your acceptance letter for Hogwarts! You learn spells and make friends and go on zany adventures. But there's a twist. Your brother, Jacob was expelled from Hogwarts for opening the "cursed vaults" and is now missing. Somehow the vaults are causing havoc again and coincidentally it seems to be you that will save the day.
I like it. It's immersive, funny, and obviously written by proper Potter fans. It's also possible to get through the game without spending any money, which these days is an amazing feat in itself. The story is entertaining and you get to make friends with lots of people in the wizarding world (the story is set just before Harry goes to Hogwarts, so you get to be friends with Charlie, Bill, Tonks etc.)
The only downside of the game is that it's not finished yet, so you get so far (Currently part way through year 5) and have to wait to continue the story. Any old school Potter fan will cope with this, and remember the good old days when we had to wait years until the next book, but they do put on a whole load of interesting challenges (with rewards like outfits or pets) to keep you busy while you're waiting.
I'm sure I'll waste many more hours on this!
Current book 2 status: Julia's trying to console a crying naiad.