Note: I will start this review by stating that I have never read a single page of a "Harry Potter" book, have never heard anything about the characters and simply know little in general about the stories and locations that the novels open up for readers.
That said, while I can't discuss the similarities or differences from the book to the film, I can discuss whether or not those who are unfamiliar will enjoy - and I think they will. Director Chris Columbus and writer Steve Kloves have included enough discription and story elements that those who walk in knowing little or nothing about Harry Potter may not be guaranteed to enjoy the film's events, but at least they should understand what's unfolding.
Speaking of director Chris Columbus, his addition to this picture did somewhat concern me, as I've strongly disliked most of the director's pictures (especially the recent "Bicentennial Man") and his general heavy-handed and often sappy style of storytelling. I'm pleased to say that, aside from a few moments of nutrasweet, "Harry Potter" remains quick and lively rather than grounded by cute moments, which could have happened with the story's fantasy elements.
The story revolves around one young lad named Harry Potter (Daniel Radcliffe), who, as the story opens, lives with his horribly mean Aunt, Uncle and Cousin. One day, an owl swoops in and drops off a letter addressed to Harry. It's ripped up by his uncle. Again and again, letters are dropped off by this rather magical form of airborne delivery until a legion of birds sit outside and await the message's reception. When it appears as if Harry's never going to get the letter, an assault of them suddenly rumble inwards, coming from the outdoors to the indoors via any available opening. It's an entertaining moment, as a hurricane of what seems to be thousands of envelopes enter the room and fly about.
Pleasantly enough, I found the entire first third of the movie to be wonderful: clever, well-acted, imaginative and energetic. Obviously, Harry eventually leaves, thanks to Rubeus Hagrid (Robbie Coltrane), a friendly and talkative giant who takes Potter on a journey to Hogwarts School of Witchcraft and Wizardry. Prior to his arrival, the movie offers up another imaginative sequence where Harry buys his school supplies, which includes figuring out what magic wand is right for him.
On his journey to the school and once he arrives, Harry meets up with a legion of other characters, such as friends Ron Weasley (Rupert Grint) and Hermione Granger (Emma Watson, in a performance that demonstrates terrific timing and great humor) and enemies, such as Draco Malfoy (Tom Felton). There's also the staff, including Dumbledore (Richard Harris) and other characters played by Maggie Smith, Ian Hart and the always superb Alan Rickman, who is excellent again here in a small-ish role.
Once at the school, Harry realizes that something's not quite right. It's up to Harry and friends to figure out who the enemy is and what it is that they're seeking. I won't give away more than that, as I don't want to ruin some of the film's suprises for those who aren't familiar with the stories. Those who have read them already (and that's a massive audience) already know what the story holds.
As I stepped out of the theater, I wasn't quite sure how I felt about the movie. I certainly thought that it was great, but I couldn't quite put my finger on what the film didn't quite deliver to bring it beyond the level of simply being "great". Pondering further, I believe what I had the problem with was the middle of the picture, which, although often entertaining, does have the picture starting to spin its wheels a bit. It's not that I was ever bored throughout the entire thing, it's simply that there are parts in the middle that I felt didn't quite offer the same level of consistent energy and suprises around every corner. What I felt as if I'd seen were: a great begining, a good - but occasionally inconsistent - middle and a respectably entertaining finish.
The three lead child actors are on-screen for the great majority of the picture and one of them could have really sunk or negatively effected the picture (as it did with Lucas's "Star Wars: The Phantom Menace"). Thankfully, all three are quite good, although Emma Watson gets the best lines of the three and delivers them with excellent timing. Technically, the picture is marvelous. The great John Seale ("Perfect Storm", "The English Patient") delivers gorgeous cinematography, production design is magnificent and the John Williams score is stellar. Last, but not least, the visual effects, which are done by Cinesite and Mill Film (who also worked on "Tomb Raider"), as well as Sony Pictures Imageworks, Industrial Light & Magic and Rhythm & Hues, are often outstanding and only once or twice just "okay".
Adults seem to be a bit worried about whether or not kids will stay interested for the entire 150 minute running time - both those who are parents and those who are not are likely nervous that they'll find themselves in the middle of a showing with several disinterested kids running up and down the aisles. While I think the film might briefly lose the attention span of some children, I think it's busy and entertaining enough so that this shouldn't be too much of a problem.
Overall, I was suprised and pleased with the film. I still don't think that Chris Columbus was the best choice to direct this or the next "Harry Potter" movie, but this picture really turned out quite well, aside from a few minor concerns.