Well, this was only the movie script, and I can only imagine how the coursebook might be. Dear God, isn't it a relief to relapse into that world, and especially if Rowling herself creates it. Mind you, I couldn't help but compare between the playwright Harry Potter and the Cursed Child and this one, and the difference is so stark. Both have good stories - maybe Fantastic Beasts has less complicated a plot as The Cursed Child - but the latter comes nowhere close to the heart-warmingness of the former.
As I said, the plot is quite uncomplicated; though a background on Harry Potter's universe would enable readers/audience additional squee-worthy moments - for instance SPOILERS AHEAD the locket that Graves lends to Credence, the Lestrange reference, Grindelwald, Newt's Hufflepuff scarf and so on. Javob Kowalski's character is a delight, an absolute antithesis to Dudley Dursley. Kowalski is an aspiring Muggle baker trapped in the daily grind of a canning factory, and his world is turned upside down - quite literally - when he gets unwittingly sucked into the realm of Newt's world. The two witches - Porpentina and Queenie - complete the gang. Porpentina - Tina for short - is an Auror who got demoted following her violent outburst at the one of the witch hunters; her sister Queenie may not as ambitious, but is exceedingly kind, loving and beautiful enough to turn the head of the Muggle (or No-Maj in the American parlance) Kowalski.
Having seen the movie - and wishing I had a niffler or a bowtruckle for a pet - I bought the book (or the screenplay, if you may). If anything, reading it was even better. Now that I had all the scenes in my head, I could only marvel at her choice of words which couldn't have been more apt to describe whatever I had seen. Rather, the writing brought out better the depth of Newt's feelings towards his flora and fauna (though partial as I am towards Redmayne, I think he too did a fantastic job of developing a chemistry with his brood). Credence reminded me strongly of Dumbledore's sister Ariana, and my heart went out to him. Rowling excels at describing emotionally vulnerable characters such as these, be it in her flagship world of witchcraft and wizardry, or in her other works like The Casual Vacancy and the Cormoran Strike series. Living our daily lives, we get bitter and inconsiderate; we forget the traumas we must have faced ourselves, too mired in living in the present and judging people basis our reactions and experiences. Little do we spare for the different, we do not stop to fathom the reasons and pass our judgements in a reflex. Rowling's work, besides providing the obvious charm of a world I can happily escape into, keeps us readers firmly grounded in the realities and nudges us towards being bigger at heart. I cannot speak for others, but it does me a lot of good to have a characters guide like Harry or Newt or Neville or Hermione to look up to.
It may be a good thing that Rowling stopped penning more on the life of Harry Potter and has begun on this project concerning Newt (as you all must know by now, there are expected to four more movies based on three books on Newt), given that wizardry universe is no smaller than the Middle Ages of The Lord of The Rings and needs spin-offs to clarify and further root our understanding and appreciation of certain characters. As for this particular installment, its a mighty brilliant start and has already set the pace pretty nicely for things to come.