This is one awful movie!! Some people told me that it was not that bad actually but I sure disagree! The monster is amazingly cheap (and funny) looking but this is something we all knew I guess. In addition to that, the dialogs are awful and the writing is just plain terrible.
As bad as it is, this movie as the quality of being entertaining. Not always for the good reasons but it's a good "so bad that it's fun" flick.
By the way, there's no such thing as "La Castagne". According to a secondary character in the film named Pierre (described in the movie as a French Canadian), there's a legend among French Canadians about a giant bird know as "La Castagne". As a French Canadian myself, I can assure you that I never heard of such a legend. It sure made me laugh though... :))