Unsurprisingly, it's really, really good.
So, let's start with the good:
I've only played the prologue, which featured no Trials, and very little Phoenix Wright, and I'm already having fun.
The puzzles were amusing.
The presentation is exquisite, voice acting is charming and both Nick and Maya's voice actors fit their characters perfectly. The graphics are beautiful as well.
What I didn't like:
Supernatural entities? It seems the game will involve the supernatural. I don't know about Layton, but Phoenix Wright has always been grounded in reality. More or less. It might've a few quirks, like Apollo being able to tell when someone is lying, or the Fey family being able to channel spirits, but the assassinations have always been relatively plausible. But now we are involving witches, witchcraft, crow-like witches with telekinetic abilities... I'm pretty sure this game will have trials, but if we involve the supernatural into it... then 'A wizard did it' would be a great excuse as any to get outta trouble! 'Oh, a witch left my fingertips on the crime scene.', and it'd be totally valid since witches do exist now. But to be fair, I've yet to play as Phoenix, so let's see how the game goes about it.