I was a bit hesitant because I already know how to play rpgs solo, have played a solo dungeon crawl with 2nd Edition AD&D fashioned after Diablo, and I've played Castle Ravenloft.
What finally got me to buy the book was when I saw the Boardgamegeek page and saw how people were customizing the game and expanding on it.
Along with all the affordable add-ons being released for it, the customization of adventure content has really grabbed my interest.
That, and it's a lot less cumbersome than AD&D. Especially if you factor in four characters.
I wouldn't mind a guide on how to create custom classes, but I doubt we would see something like that until after all the official classes have been released.
This is something that eventually hurt Castle Ravenloft for me.
Meanwhile, I can collect all the monsters and make my own vermin, minion and boss charts to fit the theme of my games.
I also like that playing a campaign is possible, but it's left to the player to define as they see fit.
This way, new players have a game to play that's focused more on the dungeon crawl experience. As they get accustomed to that, they can add a village or a regular travelling merchant to slowly introduce campaign elements at their own speed. If that's what they want.
Good job on finding a good balance between rpg and board game and solo play.
And a special thank you for making something of such quality for solo players, who (contrary to popular belief) don't just play solo because they don't have a group.
[5 of 5 Stars!]