system
A chat on subreddit /r/pcmasterrace
human
I don't think it was a marketing stunt. Just being "Harry Potter" was enough to make the masses interested. The fact that the game actually looks really good in the gameplay trailers also gave gamers massive hype, even if you're not necessarily a Potter fan.
gpt
Saw a YouTuber play the game with early access, and the game looks just as good as in the trailers. Besides the texture pop in, though he was playing on console. Besides that minor issue, the game looks just how it does in the trailers.