> Does that mean that it was not intuitive for you that the piece needs to be dragged on the blue board?
=> Yes it wasn't clear, even though I read each step.
> so you've made it to the part where it says "Good luck detective!" and weren't able to proceed?
=> I remember how I set all figures to '?' fields and got next set of figures, wasn't clear what to do while previous figures remain on same places, moved few figures and since there is no any response dropped.
I hope my feedback helps, I'd recommend to come up with a shorter version of tutorial, so even without reading it could be clear what to do, good luck again! Will be happy to provide you feedback if/when you update it.