Ahead of this Friday’s official opening, theater critics have released their reviews of Harry Potter and the Cursed Child.

A quick check of the critic reviews at various trades finds largely positive reviews for the official “eighth story,” though naturally each writer had a qualm or two.

For this round up we’ve selected passages from the reviews that don’t give away any spoilers, but beware: Anyone who’s looking to go into reading The Cursed Child spoiler-free should avoid reading any of the full reviews. We also suggest avoiding the photo section on The Cursed Child’s website, as some of the stills have what we would consider spoilers.

THR’s review is glowing, and this section in particular is something I agree with wholeheartedly after seeing the play myself in June:

Surprisingly, it turns out that the medium of theater is a better fit for the material than film, because in a theater magic tricks really look, well, magical. No one speculates with awe these days over how filmmakers can make a boy fly on a broom, or a dementor float, or one character transform into someone else on the screen because the answer is always pretty much VFX. Yet, when this production uses a simple lighting trick to suggest a ripple in the fabric of time, or makes someone disappear in a phone box (almost literally the oldest magic trick in the book), these dusty theatrical sleights actually draw gasps and applause from the audience — perhaps not unlike the first stage audiences for Peter Pan.

Variety touches on something I suggested after seeing the play myself:

Rowling has found a neat way to revisit her original, allowing for both novelty and nostalgia. Without giving those secrets away, her plot has shades of fan-fiction to it, revealing the past anew and prodding at its possibilities. It’s built for aficionados, of course, and while flashbacks and (clunky) exposition fill in the key plot points, you do need a knowledge of the world itself, from floo networks to Dementors’ Kisses.

EW’s review is largely very positive and they give it an A-, but they offer these critiques:

The performances are probably the most work-in-progress aspect, and felt like they were still coming together. There are many shouted deliveries that recall Rowlings’ Order of Phoenix-era tendency to floor her caps-lock to prove characters are REALLY UPSET. (I kept also being reminded of George Lucas’ giving his famously unhelpful direction to actors in Star Wars: “Faster and more intense.”) As Harry, Parker certainly looks the part and seems to have taken cues from Rowling’s characterization and also Daniel Radcliffe’s performance in the films. Dumezweni’s Hermione captures her character’s sternness but the script has sadly shed the fan favorite’s infectious passion and curiosity (blame the passage of time?). Best of the trio is Thornley, whose dad-joke-ready Ron seems spot-on. The three are like a distant radio signal of character familiarity, drifting in an out, only sometimes seeming to channel their iconic past.

The Guardian on the sets:

If I’m honest, I got as much pleasure from the staging as from the convoluted story. Tiffany and his designer, Christine Jones, have created magic out of the simplest ingredients. The set is dominated by Victorian gothic arches, more reminiscent of St Pancras than King’s Cross, and by the brilliant use of suitcases and portable stairways. An exciting escape on top of a moving train is evoked through a line of luggage and the estrangement of Albus and Scorpius is suggested by flights of steps that move as nimbly as Fred Astaire. Harrison’s magic, Katrina Lindsay’s costumes and Neil Austin’s lighting achieve triumphant fulfilment in the creation of the Dementors, dark forces who suck the souls out of humans and who float through the air like wraiths.

One of the brightest reviews comes from the UK’s The Stage:

But I can happily shout out from the rooftops of the Palace Theatre – of all the theatres in the West End the one that most resembles Hogwarts – that this is a major work in its own right, with an entirely distinctive theatrical life and shape.

It earns its place on the stage, feeling distinct from both the books and the screen adaptations. By turns playful and gripping, disturbing and detailed, poignant and powerful, it is superb family entertainment.

[…]

Harry Potter and the Cursed Child is no cynical attempt to cash in on one of the most successful literary franchises of all time. It has real integrity and, crucially, could prove to be one of the most influential and important theatre works of the century, introducing whole new generations of people to the joys of theatre.

[…]

I saw both parts of the play in a single day – more than five hours of theatre – and the audience was one of the most attentive I have ever been in. The house was virtually full 10 minutes before curtain up and the sense of eagerness and expectation was palpable. At the end of each and every act, the audience roared their approval. But this is far more than just a show for the fans – it’s a truly game-changing production and a thrilling theatrical endeavour in its own right.

And finally, TIME addresses the concern over this being a play instead of a book:

Cynics have suggested the decision to split the play into two parts rather than one smacks of commercial exploitation, echoing the way the final book was broken in two on screen. But Cursed Child could only be told over the five hours that splitting it into two allows. It’s a fiendishly complex narrative, and moves at a lick; the first two years of Albus’s time at Hogwarts are told in the first fifteen minutes. Considering each of the books covers the course of a single year, this marks a radical change of approach.

While many Potter fans might have preferred a new movie or a book, this is a story that feels made for the stage. Yes, it’s packed with effects as characters cast spells, fly and even transform, achieved through old school stagecraft rather than digital trickery. But Thorne and Tiffany also conjure up moments of intimate drama; it’s telling that the biggest gasp in Part One came not from a twist of the plot or a moment of magic but during a blazing argument between Harry and Albus where the father firmly crosses a line. In these scenes between father and son, Jamie Parker as Harry captures a sort of tortured celebrity anxiety, suggesting his concerns about Albus’s shortcomings are in part driven by ego, and in part an orphan’s struggle to connect with his child.

The Cursed Child officially opens on London’s West End on July 30. The book will be released around the world on July 31.