I started this thinking it was going to be a fairly standard samurai movie (not that there's anything wrong with that!), but found out right before starting it that it was actually a version of Cyrano de Bergerac, except with samurai. This made it sound much more interesting, because I've seen a few takes on that story (off the top of my head, two direct adaptations, and Electric Dreams from the 1980s, if that counts), and it's always a satisfying tale.
I feel like it works pretty well here, but anyone expecting it to be the kind of Western-to-Japanese adaptation that someone like Kurosawa pulled off with films like Throne of Blood and Ran might want to temper their expectations a little. Maybe that's where my mind went, because Toshiro Mifune plays the lead role here, and though he was in plenty of great non-Kurosawa movies, it's sometimes hard to think of one of those guys without thinking of the other (I also watched High and Low last night, so that might be another reason for that).
Mifune's really good here, delivering a performance that can be equal parts funny and tragic. And the story here's fairly compelling, even if it's very direct of an adaptation, meaning those familiar with the narrative might find it a little less compelling/surprising as a result. But for good acting, solid filmmaking, and a little action here and there to keep things exciting, I'd say this makes for an overall pretty good time, and its positive qualities make Cyrano de Samurai worth a watch for fans of samurai movies and/or Toshiro Mifune.