The Daily Telegraph's Anita Singh gave it four stars out of five, saying it was the "scarriest Potter film so far". She says it manages to be "sweet, funny, and tear-jerking all at once".
Allan Hunter in The Daily Express gave the film, which has a 12A certificate, five out five.
He said it delivered ''everything you could want - from dazzling special effects and spellbinding storytelling to breath-taking excitement and heart-in-the-mouth emotion''.
Ralph Fiennes was praised for his ''slippery, slimy, supremely menacing Lord Voldemort'', while Helena Bonham Carter's Bellatrix Lestrange is ''more demented and dangerous than ever''.
Overall ''the tension never fades amid desperate chases, frantic escapes, titanic battles, noble deaths, electrifying encounters and enough humour to break the tension every now and again''.
The Guardian's review was markedly different, describing the film as a ''prolonged death rattle'' and rating it just two out of five.
Deathly Hallows feels ''largely indistinguishable from the six outings preceding it'', the paper said, while the mission to evade and defeat Voldemort is ''the same as it ever was''.
Director David Yates' effort was also described as ''looking great, in the way that a show home looks great'' while the roster of stars ''flit between the scenes with the satisfied air of jobbing actors who have been offered walk on roles at the world's most expensive fancy dress ball''.
The review also questions the long-term appeal of the franchise, saying: ''I can't shake the suspicion that these films are too obviously built for purpose and too lacking in wit, warmth and humanity to survive much beyond the moment.''
The Daily Mail's Baz Bamigboye avoided broad-brush judgment, reserving instead most praise for Emma Watson's performance as Hermione.
He said: ''Emma Watson...has cast her spell over me. She's mesmerising in her quiet, methodical, no-nonsense way, and is definitely the heat source in this movie.''
The critic said this, the first part of the seventh instalment, was more ''earthbound'', taking viewers out of Hogwarts on a ''road trip of sorts''.
But he noted that the stories ''still have power to enchant you, and bring you to the edge of your seat'', and that there ''are some breakneck chases, thrills and spills that should appeal to all''.
One slight criticism was the film's length of 146 minutes, with Bamigboye saying: ''I'm sure there must be a spell that could have made at least 20 minutes disappear''.
James Mottram in The Independent awards the film four out of five, saying it is an ''appetiser that will leave Potter fans hungry for the finale''.
He hails some ''beguiling scenes'', including the moment when seven friends turn themselves into Harry to act as decoys.
But the picture struggles because it ''sags when it should soar'' - especially in the scenes when Harry and Co hit the road to seek out a series of artefacts.
Mottram also says the film feels over-stretched, but concludes ''your appetite will be whetted for what promises to be an almighty showdown before the curtain comes down on Harry Potter for good''.
The Times' Kate Muir rates the film three out of five, saying many will wish the ''bloated finale'' has been edited down into one ''zappy film''.
She describes it as the darkest Potter film yet, featuring killings, show trials and ''the wizard equivalent of waterboarding''.
A ''nightmarish place'' for five-year-olds, Part 1 is ''clearly aimed at tween or teen readers who grew up with the books, and will have no choice but to graduate with The Deathly Hallows Part 2.''
''The problem is a lack of forward momentum,'' she adds, but ''relief comes with some big set pieces''.