I thought it was pretty awful to be honest. The characterizations for some characters were so badly off at times. It read like a fanfic.
That's not really the point. Whether it's a play or a novel, the characters should feel like the same characters we read in the first seven books. I mean they reduced Ron to a joke in the script and Hermione barely showed any of her personality. And I couldn't believe that Harry, the guy probably most experienced in what loneliness and being singled out is like, could not understand his son when he had the same predicaments. It's amazingly out of character. And again, nothing excuses the stupidity of the twist. I am never going to buy that Voldemort had a child. The guy's entire focus in life was to be immortal. Why on earth would he want and heir? Then there was some ridiculous timely whimsy stuff which didn't even make sense when you look at the concept of time turners as introduced in POA. It's a pretty terrible script.