The Mail calls Spider-Man: Homecoming "the blockbuster of the summer", while The Guardian calls it a "light, snappy and frequently hilarious crowdpleaser".
According to Screen Daily reviewer Tim Grierson, British actor Tom Holland - a former star of the Billy Elliot musical who turned 21 this month - "makes for a believably underage Peter Parker".
The Hollywood Reporter, though, says "a charming new lead only goes so far".
Jon Watts' film, writes critic John DeFore, is "often frustrating" and "represents a creative mis-step" for the Marvel Studios.
Largely set in New York, Spider-Man: Homecoming follows on from Holland's introduction to the "MCU" - Marvel Cinematic Universe - in Captain America: Civil War.
That 2016 film saw Spider-Man - a teenage crime-fighter who can spin webs and swing between tall buildings - participate in a battle between Captain America, Iron Man and other superheroes.
The new film sees Spider-Man's alter ego Peter Parker juggling his high school responsibilities with his secret life as a masked vigilante.
It is not long before he encounters Adrian Toomes, a villainous arms dealer who has his own alter-ego in the form of wing-sporting marauder Vulture.
Previous versions of the Spider-Man franchise featured Tobey Maguire and Andrew Garfield in the title role.
According to Digital Spy, "Spider-Man: Homecoming's biggest achievement is that it makes you forget it's the third different Spider-Man - and second reboot - in less than 20 years."
"There's a spontaneous charge to the film, a euphoric innocence, that makes it a much-needed antidote to stale franchise formula," raves Rolling Stone's Peter Travers.
Variety's Owen Gleiberman, meanwhile, praises the "sinister, gnashing personality" Keaton brings to his role while wishing he had been "given more to do".
"Homecoming is easily the best Spider-Man film since Sam Raimi's operatic Spider-Man 2," concludes Empire's Nick De Semlyen, one of several critics to give the movie four stars out of five.
Spider-Man: Homecoming opens in the UK and Ireland on 5 July.
Superhero movies are like garishly costumed buses at the moment. If you happen to miss one, there's always another one just around the corner.
That's partly down to the way character rights have been divvied up between the studios, who all want a piece of the comic book pie.
Spider-Man is a case in point. He was created in 1962 by Marvel, now a subsidiary of Disney. But he's effectively owned by Sony, who have made five Spider-Man films since 2002.
The success of the Avengers films, though, has inspired Sony to loan him back to Marvel, allowing him to share the screen with the likes of Captain America and Iron Man.
It's a strategy that reaps dividends in Spider-Man: Homecoming, which features Robert Downey Jr's Iron  Man in a supporting role and humorous cameos from Chris Evans' Captain America.
Yet the film also works satisfyingly as a stand-alone superhero teen movie, mostly thanks to the immensely likeable Tom Holland.
The young British actor - not to be confused with Rev's Tom Hollander - has a pleasing boyishness and excellent comic timing in a film that is laugh-out-loud funny when it's not noisily thrilling.
Michael Keaton is also good value in a villainous role that ingeniously plays on his work in both 1989's Batman and the Oscar-winning Birdman.
There is an unexpected moment midway through Spider-Man: Homecoming that had last night's press audience at the Odeon Leicester Square in London bursting into spontaneous applause.
The film is not without faults and is at least 20 minutes too long. Given how familiar the genre has become, though, it speaks volumes that the film still has the element of surprise.
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Reviews are in for the new Spider-Man film, and they're mostly positive.