Agneiszka Holland does an outstanding job directing this film. Each character is separate and unique; each one has little personality quirks that makes it seem real. Just about every scene in the movie includes children, animals, or both -- which must have been a nightmare to coordinate. Ms. Holland pulls it off without a hitch. Everything melds perfectly, and we are transported to a distant place and time, and fall in love with real, human characters.
The primary three characters in this story -- Mary Lennox, Colin Craven, and Dickon -- are all children, played by actors who are around 10 years old. Ordinarily having one child in a movie is difficult enough, but again, somehow they pull it off. All three kids -- especially Kate Maberly -- do a fine job of acting, and they are quite credible. Kate is simply divine as Mary Lennox, and Heydon Prowse was a good counter-point to her as Colin.
The story is touching and charming, and I think you'd have to be almost inhuman not to have a tear in your eye by the end of it. I absolutely fell in love with these children, and came to care very much about their characters. The "secret garden" really does seem to be a magical place (and I will say no more about it, since otherwise that would spoil things), and at the end I found myself wishing I could go and visit it first-hand. The accompanying music is wonderful -- I find myself humming it for days and days after watching it.
In short, everything comes together to make this film a masterpiece. It is easily one of the 10 or 12 best movies ever made, perhaps *the* best movie ever made. I love it so much that I went out and bought the DVD of it, even though I'd seen it 8 or 10 times already. If you have not seen it I give it my highest possible recommendation. My score: 10/10.