True to the early pages of the book, "Everyone In My Family Has Killed Someone" is a modern mystery following the pattern of Golden Age classics so if you grew up with Nancy Drew or Agatha Christie it has a somewhat nostalgic feel. The narrator--who is writing this book about his own experiences--sometimes comes off as smarmy and a know-it-all when he uses his meta knowledge to tell you about events just before they happen; thankfully, he backs off before it gets really annoying and his use of meta knowledge becomes a charming quirk of the writing.

I have some complaints about the reveal at the end of the book, where all the clues come together in classic detective novel fashion. Despite priming us by insisting he won't break the Commandments at the front of the book

the author clearly breaks Rule 4 with the use of microdots which are never well explained making every revelation involving them downright confusing; they easily could have been revealed sooner without jeopardizing the twist. Similarly he plays fast and loose with his responsibility as the Watson: telling the reader his thoughts as per Rule 9.

In short too much new information was revealed making it impossible for readers to solve as they go along, which makes the prologue's instances that he won't lie nor break the Commandments of Detective Fiction kind of a waste of type and the reader's good will. A good mystery never needs to pull a fast one on the reader.

The setting is fun, the slow reveal of how each family member embodies the title is exciting, and the inferred moral derived from which family members count towards the title's claim (who does "My Family" include) is a charming theme that is well explored.