I will keep this brief.
There was little I liked about this book. The little there was were the three young characters Albus, Scorpius, and Rose. I loved that they were not cast as repeats of their parents and that their background did not determine their character or actions, which, I guess, it the main message of the book/play.
That was it.
Other than this....oh, dear.
The story is like a Greatest Hits compilation of all the best loved or most famous parts of the HP series that is thrown into a mix with Back to the Future.
None of the characters from the original books were anything like they should be.