OK, this movie is no Lord of the Rings, or even Crouching Tiger.
So what? It might not be a masterpiece of world cinema, but it's rather fun.
The plot is cheesy (big plot holes as well) and the love story severely cliché, however the art design and sets are beautiful, the fights fun enough (though a bit puzzling), the leads are all appealing and there is melodrama and angst galore.
Yeah, you could do better (Hero, House of Flying Daggers, Musa). But if star-crossed lovers, revenge and period movies are your thing, and you don't mind a few bits where the plot is confusing and/or over-the-top, you can do much worse than Bichunmoo.