Okay, this one was a disappointment. Not that bad but not good either. 3 out of 10.
Having an ingenious timeline and a clever solution and an eccentric detective and a very video-gamey setup are all plusses in my book. The meta-stuff “let us admit we are characters in a novel and not make excuses” is tired now but perhaps wasn’t when this book came out in the thirties.
But what then sinks the book somewhat—not all the way to the bottom, but down from the lofty perches of modern classics, is unclear, dense, overly witty writing without clear attribution to who is saying what when. This would work better as a comic book since it’s a formless of talking heads where you always need to keep careful track of parity to know who in saying what.