I ran the cinderling adventure as a one shot yesterday and both I and my players loved it! It is very charming, in a way that doesn't get old by the end, and made a player want to permanently keep a cinderling. All the little silly quirks of the cinderlings and the flavoured optional encounters really help to establish the right mood, and the freeform nature of the encounters helps with pacing (we took about 3,5 hours for two players). It kept us adults entertained, but it would also work great for younger children's first adventure.
I'm looking forward to trying out the other adventures soon : D
[5 of 5 Stars!]