Why McEwan's Nutshell misses the mark

Tonight book group will discuss Ian McEwan's Nutshell; have been re-reading it, and my thought at the moment is that it's less that the sum of its parts. McEwan has 2 tricks going at once, and at times in conflict: a novel narrated from the POV of a fetus, and a retelling in contemporary setting of the story of Hamlet. Taking the first "trick": OK it's clever at times, as at the outset when the fetus/narrator has a sense of what people look like but no idea what the color "blue" actually is (is there any way to describe colors to someone born blind?), but McEwan doesn't do much w/ the obvious limitations of the fetus - in fact the narrator is as knowledgeable and worldly as ... McEwan. The explanation?: he hears a lot via the podcosts is mother listens to. OK. Second, the Hamlet story. Well, it just does not work in the 21st century; people just don't go around poisoning one another - it wold require a completely deranged person to so that, and the central characters - Trudy and Claude, ha ha, are selfish, foolish, reckless - but not murderers, sorry. The strengths of the novel are the narrator's, i.e., McEwan's shrewd observations and verbal riffs; two that came up early in the narrative a litany of all of the global crises or our time, and, as a counterweight, another litany about all the ways in which science and technology have given us a better life. These are fun to read tours des forces (?) but in the end they are peripheral to the narrative itself. In the 2nd half of the narration, the narrator at last plays a role in the narrative, forcing a premature birth to derail the escape plans of Trudy and Claude - but how does McEwan tie this to the Hamlet story? He doesn't. I thought maybe the child would be born, christened Hamlet, and a revenge plot set in motion? But no McEwan just abandons ship. He still stands as one of our finest contemporary writers in English - Atonement is one of the finest novels of the past 25 years w/out doubt, but his is kind of a one-off.