"Freeman wields the same sort of understated comic timing as Bilbo, a fussy homebody who decides that he needs a little adventure in his life," says Tim Grierson of the Screen Daily.
"Jackson has crafted a Middle Earth that is just as evocative as it was on film a decade ago."
Opinion is sharply divided over Jackson's decision to film at 48 frames per second (fps) - double the standard 24fps usually seen in films - which creates a hyper-realistic look.
Only selected theatres will screen the film in this format.
The Herald Sun reviewer Neala Johnson says the 48fps is at first distracting.
"Somehow everything looks TOO real. From the wizard Gandalf's wrinkles to the rolling green meadows of Hobbiton, everything is brighter, crisper, as eye-poppingly colourful as kids TV."
But like McCarthy, Johnson notes the 48fps comes into its own during battle scenes.
The Sydney Morning Herald's Gary Maddox says the adaptation is a dark, spectacular adventure.
"Some fans may resent the liberties with the novel, some might not go for (wizard) Radagast's eccentricities, but An Unexpected Journey has so many pay-offs that most are likely to re-engage with the saga," he writes.
US film critic Jordan Hoffman of the ScreenCrush website is unimpressed by the 48fps.
"Anything shot in daylight looks like a BBC production from the 1970s. The movement is too smooth. And yet, when the camera moves, too, it looks somewhat jerky."
But he likes the movie, sort of, writing that "despite its many gimmicks, (it) is just an okay movie".
Peter Debruge of the influential Variety, says The Hobbit delivers "more of what made the earlier trilogy so compelling" such as colourful characters amid "stunning" New Zealand scenery.
On public film review website IMDb over 6000 people had rated The Hobbit giving it an overall rating of 9.2 out of 10.
Dave Trumboe of the popular Collider website says the film is a "stand-alone adventure classic" but expects the next two instalments of The Hobbit will be even better.
* Read the Herald's review of The Hobbit here.
- AAP