Roger Corman goes for it and delivers one of the landmark B movies of the era. Objectively ropey it has charm and some good ideas mixed in with its famous mildly explotative Star Wars cash-in take on Magnificent Seven/Seven Samurai.
Things like the Nestor clone infiltration gambit to attack Sador directly are really great. It's a scene I remember vividly from when I saw it at the cinema.
It's second tier filmmaking that had more impact/longevity than a great swathe of nominally first tier material that now languishes forgotten. Recommended 8/10 for what it represents rather than what it is.