While I really enjoyed a lot of the character development for previously built characters (for example, Draco was great, and I loved that they addressed Ginny's experience with Voldemort, as that's one of the reasons Hinny is a great ship and I support it), and I really enjoyed Scorpius, a lot of this play read like fanfiction. 
 I'm aware that it doesn't read like a novel because it's *not* a novel, but the plot feels very forced, and it damages already established laws of the Harry Potter universe. It takes the potency away from the events of POA, and while I enjoyed The Cursed Child while I was reading it, I'm not left with any feelings of satisfaction. 
 Ultimately, I'm annoyed that the play reduced characters to one-liners (hey there, Ron - also, where is George?), that characters behaved in such out-of-character ways (just saying, there's no way that anyone was calling McGonagall by her first name. It's Professor, or Professor McGonagall, or Headmaster... no one would address her by her first name as if they were neighbours borrowing sugar), and that Albus and Scorpius' relationship was clear gaybait. Unlike some reviews I've seen, I do notice the hints to Scorpius' feelings towards Rose, but I still think that the ideas of romance in this play are weird. 
 Also, good luck trying to convince anyone that character assassination was a good idea. You know which one I'm talking about. Not cool, and not even a little bit believable.