To start by saying the storyline and poster on this page do not relate to this movie. There are no ninjas in it, and I suspect 'Ninja Fist of Fire' is a different film. There is a prince hoping to 'gain his rightful place on the throne', but he is a frightened child with no fighting ability.
The setup is fairly typical. We have a group of good guys, an aged lord aiming to restore the prince, assisted by a reluctant knight and the star of the show, a wandering female mercenary (Ching-Ching Chang). We have the usual row of bad guys for them to knock over. The dubbing on the version I saw was better than some, the action kept moving (though sometimes in rather random directions) and I found it entertaining throughout. The fight scenes were well-enough done, but mostly not that inventive. There were quite a lot of battle-type scenes, rather than individual duels.
As for the more original aspects: In her fights, Chang often uses stratagems, like feigning injury, rather than just being better than the rest (which she clearly is - for once she's allowed to comprehensively defeat the supporting good guy). Her personality is more interesting than usual. Rather than yet another goody-goody, bent on revenge, she kills a group of soldiers gratuitously, is not above negotiating a huge payment from the friendly old lord, and her jokey, super-confident persona is great. 'It might be difficult for YOU,' she tells the main bad guy. 'For me it's easy as pie.' The supporting knight, rather than a stock hero, is surly, bad-tempered and reluctant throughout - a very nice touch. And while the main bad guy isn't a nice man, it seems he may well also intend to put the prince on the throne - for the advantage it will bring him no doubt.
This has a somewhat different feel from the standard wuxia flick and it's 90 minutes of very fun entertainment.