I figured out whodunnit about a third of the way into The Yellow "M"
but still enjoyed the story, which is one of the marks of a good mystery for me. I loved the artwork and the feel of this comic.
I can't help thinking of Blake and Mortimer as a sophisticated Scooby Gang, which is a comparison that doesn't really make sense. It's not a negative, though -- I'd definitely read more of their adventures.