This is a great companion piece to Kaneto Shindo's Onibaba. I happen to prefer the earlier film, mostly because of the settings and atmosphere, but there's a lot to admire here. The film starts off strong, with a grim and brutal opening scene that's well done. It sets the mood for what is to follow.
Whereas Onibaba is very much a slow burn film, this movie sort of jumps right into the supernatural elements, which I think actually helps the film remain unpredictable. You're not sure exactly where the story is taking you. The first few attacks on the Samurai are well done, suspenseful, and I like how they seem to get easier as time goes on.
Once the protagonist comes into play, the viewer is conflicted; up until now, you can sympathize towards the ghosts, because of what happened to them, and we have no investment in the Samurai they attack. However Gintoki seems like a good guy and you kind of want to see him reunite with his family.
Gintoki's orders to slay the ghosts while still being in love with his wife, and his wife's sacrifice to immortality just to share a few nights with him, add some interesting depth to what could be a typical ghost story.
The finale is creepy, if a bit bewildering. It's a bit frustrating to see Gintoki open the temple to what must obviously be the remaining ghost. But I don't think it really hurts the film much. I do prefer Onibaba, but this film is different, and good enough to stand on its own, and is certainly worth a viewing.