No wonder that California isn't as popular as so many other Spaghetti-Western. It is entertaining but not funny like My Name is Nobody or violent like Four of the Apocalypse. IMO California is one of the last real Spaghetti Western but the filmmakers didn't want to do a typical Western. Somehow it reminds of one of the many 50's Western flicks but with a darker a more sinister story. Maybe you can compare California with Keoma or The great Silence. Also like in these Movies it isn't so easy to say who really the hero is. Is it Guiliano Gemma as California, who hates his old name and has enough from all that Killing and Shooting? His opponent is Raimund Harmsdorf a German actor and is best known in supporting roles in so many B-Movies or German TV Shows. In California Harmsdorf has a fairly good role and he did some fine acting. He is a ruthless Bounty Hunter who kills Confederates Soldiers for Money. Unfortunately politics changes and he is getting an Outlaw. For a SW there are interesting characters and not just a faceless Hero and his Villain. Sorry but the figures aren't simply Black and White in this drama and there are no funny jokes of Guiliano.
I wasn't quite happy with this melodramatic Organ 70's like Music. In some way it fits in some not. The photography is bleach and the environment looks dirty. Towns and people seemed to be destroyed by the war and this world has nothing to do with the beauty as you can see in Once Upon a Time in the West. Some Scenes are taking place in a Ghost Town. These Scenes are very climatic and give the audience more of the Apocalyptic Feeling. The Storyline has two parts. A travel at the end of the American Civil War and then a Vendetta as it we have already seen in so many contributions to the Genre. But it wouldn't be a typical Spaghetti Western if this Vendetta wouldn't be different. California (1977) hasn't a lot in common with Gemma's first western A Pistol for Ringo (1964).
For me this melodramatic western was a big surprise. The storyline and the figures are fine written. It's not a Feel Good Movie or just another action loaded Hero Tale of the West. Of course it has some flaws and there are some weak points in the second part but overall it's an interesting flick. Director Michelle Lupo did a good job and it was his last serious western too. Buddy goes West (1981)is more a Comedy than a Western. One year later Lucio Fulci master of Giallo and Horror directed a Spaghetti Western with a similar look: Silver Saddle (1978). Guiliano Gemma is the main cast again but Fulci's Movie isn't so sinister and dark than this one. IMO these two Movies were the last Highlights of the Spaghetti Western Genre and then this fascinating Genre ended.