This spaghetti western might have been the germ of inspiration for the movie "Four of the Apocalypse", which came out five years after this one. (Though both movies only have a few minor similarities in the end.) Anyway, while "Apocalypse" has in recent years been rediscovered and acclaimed, this one has mostly been forgotten. To a degree, this is understandable. As others here have pointed out, the movie is quite slow, not only taking a very long time to set up the plot and characters, but also that the last third of the movie drags at times. Strangely, even though the movie doesn't have all that much plot elements, not only are most of the members of "the unholy four" not fleshed out well, there's at least one plot thread that's unresolved at the end.
But despite the sluggish pace, the movie does have its share of rewards. While there isn't a terrible amount of action, what there is (ranging from gun fights to fist fights) actually packs some punch, thanks to the skillful direction and editing. The musical score, while a little repetitive, is upbeat and pleasing to the ears. And while the movie is often slow and uneventful, it's a credit to the filmmakers that all the same things never get downright boring. While the movie isn't really all that memorable - I'm sure I'll eventually forget everything I saw in it - it does manage to engage and entertain the viewer while he or she watches it.