Not bad I guess? Looks like it was Shinoda's first feature, and through exploring his filmography, I've him to be a director who consistently puts out decent to good movies. None that I dislike, but also none that I can quite say I love.
This too falls under decent, though maybe on the lower end. It's less experimental or new-wavey than his other 60s films, with simple/fairly clear characters and a simple plot that's sort of there if you care, but isn't hugely important if you more just want to watch this for the characters and the overall vibes.
And there are vibes to be had. Plenty of music, and Shinoda's movies had pretty good visuals right off the bat, it seems.
Not bad, not great. As part of his early works, it helps give context to what came after (and still so many more to see from this always interesting director, who along with Yoji Yamada remains one of the last living Japanese directors of this era of Japanese cinema).