There's that old caveat about film - "willing suspension of disbelief".

To me a film is successful if it has "tone" - a mood or feeling that is established visually, and through the acting, from the get-go and maintained throughout. Also very crucial is the internal logic. It can be improbable, but if it makes sense within itself, it works.

I liked "The Piano" alot and saw it as more of a fable than a historic re-enactment. If you've seen many of director Jane Campion's other films, you'll recognize that she definitely sets up an "altered reality" in most of her outings. Like Harvey Keitel, she lets it all hang out !