This is a somewhat curious novel - written in the form of a (discounting the ghost) realistic historical novel, except set in the alternate Renaissance Denmark where a certain royal family ruled from Elsinore Castle and everybody had weird names.
I felt the early parts set in Wittenberg, where our narrator met the un-named Prince and they became friends worked the best, and I also liked the politicking post-everybody drops dead of poison bits okay. Once we reach the part of the narrative actually covered by Shakespeare's play, the whole thing just - it felt like half the story happens firmly off-stage, and you'd better have read Hamlet before sitting down to read this. I also found the characters' speech jarring - while most of the novel provided the characters with pretty standard old-fashioned historical novel Danish speech, it's very obvious whenever it's lines from the play they're suddenly spouting. It feels that bit older and more stylized than everything else.
All that said, I personally was left wondering exactly why the author felt the need to make Hamlet explicitly aromantic asexual and present that as a terrible thing to be, making it half his motivation for his toying with Ophelia - while he also carries on a platonic homoerotic something with Horatius, who in turn carries on with her, and it's all just. I could have lived without that. It's a mess and kinda offensive.