Before watching the movie:
The Seven Samurai has been remade and recontextualized and homaged many, many times. Its best known remake is of course the Western The Magnificent Seven, but pretty much every “go put together a group of mercenaries to save the hometown” story is probably based on Seven Samurai. However, I don’t think I’ve ever seen a movie do it so blatantly that the tagline itself invokes Magnificent Seven. Apparently Roger Corman wanted to do something like Star Wars and decided to do a sci-fi interpretation of Seven Samurai. So he did.
After watching the movie:
The warlord Sador arrives at the humble and pacifist planet Akir and announces that they are now under his dominion and when he returns, they must surrender most of their year’s harvest to him or they will be destroyed. The people of Akir are mostly not fighters, but the last of their old Corsairs insists that someone must go find mercenaries willing to defend Akir when Sador returns, though all Akir has to offer is food and shelter. Shad, a young man who knows how to fly the one fighting ship left on Akir, volunteers, leaving his home for the first time to be forever changed by the universe outside.
This is a classic kind of adventure story. The young hero bounces from place to place, encountering all kinds of strange things he never could have imagined. There’s a lot of work done introducing several different alien cultures and some fantastic elements that are not often seen. Shad has a clear character arc through the story even with the episodic structure.
The music is surprisingly well done, though it’s by a very young James Horner, not yet a legend. The model effects are deservedly legendary. The sets and costumes though, while varied and expansive, feel cheap, like the money went into quantity over quality. That element of the aesthetic (as well as the warm, neutral late 70s palette) gives it a Blake’s Seven feel. The Nestor ship’s control console as well bears a more than passing resemblance to the console from Doctor Who.
There’s a lot that could be expanded upon in this movie due to its sampler platter approach to worldbuilding, but it all adds up to a fun adventure with plenty of action sequences to keep things exciting. There’s a mix of famous and soon to be famous artists working together on this movie, and it’s probably no one’s high cinema, but it is certainly not disposable entertainment.
Yesterday's Movies 
The reference to Doctor Who alone, is enough for me to add this movie to my to watch list. Thank you
The sets and props are on a slightly higher quality level than I tend to think of classic Doctor Who being at (plywood rather than cardboard, but plywood that looks like plywood, when good artisans can paint plywood to look like anything) and as I said, reminds me more of Blake’s 7, but there’s a lot of overlap between Doctor Who fandom and Blake’s 7, as they’re both BBC sci-fi from the 70s/80s and Terry Nation created Blake’s 7 and long intended to import the Daleks to it. The only reason I’ve seen any of Blake’s 7 is because a local Doctor Who fan group had a Blake’s 7 watch party, and it’s certainly easy to see the family resemblance.