It's odd looking at an early OSR product written by one of the founders of the hobby, which was created before the "strange OSR" zeitgeist.
Scanning through my PDF, it seems like: "This is a historically accurate European Medieval town with details down to the types of hairpins that women of fashion wear. But also we're not including more than realistically grounded encounters with bandits or wolves." It doesn't feel especially fantastical at all.
While I'm glad this is getting re-released for completion's sake (and I'm happy to support the Gygaxes in this financial endeavor), I can't imagine this holding the interest of anyone who's entered the TTRPG hobby in the past 25 years.
I hope the Castle itself is interesting, magical, and fantastic, because Yggsburgh lacks variety and a sense of wonder.