I'm trying to find a movie that I have very very vague memories of. It is about either a family, or a just a guy, who ends up on this different planet. Nearly everyone is really really dumb.
The planet is ruled by one main bad guy, though there are rebels. At one point the main guys finds some of the rebels, and they are dressed in giant bird costumes, which our hero points out wouldn't fool anyone because there are no human sized birds.
The only other person who is intelligent is the commander of the planetary emperor's army, I think.
I think this was a 70s/80s movie, but I'm not sure. Ring any bells with anyone?
There may also have been a scene of the hero being thrown down this garbage shute, or something, and grabbing this thing to hang on from, then climbing back up?