Alien: Covenant, which is out in the UK on Friday, is the sequel to Scott's 2012 Prometheus and stars Michael Fassbender and Katherine Winterston.
The Guardian said the "parasitic space alien has returned for this watchable if unoriginal sci-fi thriller".
But The Telegraph said the film was "grandiose" and "exhilarating".
"To want more Alien after this... would be to want to see something very odd indeed," Robbie Collin continued. "But Covenant leaves the mythos feeling riper and more vitalised than ever."
In The Guardian, Peter Bradshaw went on to say: "The vu has never been so deja: It's a greatest-hits compilation of the other Alien films' freaky moments.
"The paradox is that though you are intended to recognise these touches, you won't really be impressed unless you happen to be seeing them for the first time."
The Independent described it as a "mightily impressive piece of cinematic engineering".
"Every second here is tinged with dark foreboding, with the relentless tension that marked the 1979 original," the paper's Clarisse Loughrey said.
The Mirror was equally effusive, saying: "Scott's final theatrical flourish sends the franchise spinning out in a new direction. This is screamingly great cinema."
In the US, where the movie comes out on 19 May, Variety magazine was firmly on the fence, saying the film was "more of the same, which is both a relief to fans and a letdown to those hoping it might pave new ground".
Its reviewer Peter Debruge concluded: "As acts of creation go, Scott has made an Alien movie for that segment of the audience that has always rooted for the monster."
In the Hollywood Reporter, the verdict was considerably more enthusiastic, saying the film was "gripping through its full two hours and spiked with some real surprises".
"This beautifully made sci-fi thriller will immeasurably boost fan interest in the run of prequels which Scott has recently said will consist of at least two more films until the action catches up to the 1979 original," it said.
Follow us on Facebook, on Twitter @BBCNewsEnts, or on Instagram at bbcnewsents. If you have a story suggestion email entertainment.news@bbc.co.uk.

Deborah Fenlon's Menos 4 trial will investigate how routine CBT could help patients regain a sense of control over difficult side effects.
Hot flushes and night sweats are experienced by about 70% of women undergoing treatment.
The trial has been funded by a Â£300,000 Breast Cancer Now grant.
Royal Glamorgan Hospital is one of six participating in the three-year project, led by Swansea University's Prof Fenlon.
Hormone replacement therapy, normally offered to women experiencing hot flushes as part of the menopause, cannot be used by women with breast cancer as it can increase the risk of their disease returning.
The scientists said although CBT was known to be effective, it was not routinely offered on the NHS for women with breast cancer and can only be given to groups by trained clinical psychologists.
During the study, half the women will receive group CBT from a specially-trained breast cancer nurse in six weekly sessions lasting 90 minutes. The other half will receive whatever support they would normally receive.
A 52-year-old teacher, taking part in the trial, said: "I had never expected hot flushes to be quite so awful.
"Some nights I just do not sleep as the hot sweats keep me awake and then I have to work the next day as though everything's ok and it's not."
Prof Fenlon said: "Hot flushes and night sweats can have a major impact on women's lives; affecting their work, social life and disrupting their sleep.
"There are very few effective measures to help support women with this problem, particularly after breast cancer and proven interventions are not widely available.
"With this study we hope to show how an effective intervention can be offered more widely."
Ridley Scott's return to directing a film in the Alien franchise has received mixed reviews ahead of its UK and US release.
[NEXT_CONCEPT]
A Swansea scientist is trialling how cognitive behavioural therapy could reduce the impact of hot flushes for breast cancer patients.