I've played one Descended from the Queen game, The Wizard's Tower, and quite enjoyed it even as a solo experience (which involved moving the final question card a bit up in the draw deck). I feel that this guide describes well the essence and soul of a game that uses this framework, and gives good advice for designers thinking about creating a Descended from the Queen game.
One particular detail I liked is the examples given from a few Descended from the Queen game to show what can be done with the framework, from varying the theme, varying the "queen", and varying the final goal(s).
Also the last section is more general advice about playtesting, though it has some specificity to the Descended from the Queen framework, which I feel is extremely valuable for those starting out in game design. I've known board game designers before, and these are similar principles that work there, too.