Kin-dza-dza! (1986) on Netflix

Two Humans, "Uncle Vova" and "The Fiddler" accidentally find themselves on another planet after pushing the wrong button on the strange device in the hand of an odd hobo, claiming to be an alien. Planet "Pluke" in the galaxy "Kin-Dza-Dza" looks like a desert. All "aliens" look human, and can understand Russian, after reading uncle Vova's mind. Their own language is mostly telepathic and is limited to 11 words - 10 plus "koo" - all other words. The whole paradox of Pluke is that their civilization is much more advanced than ours in time and space traveling, weaponry and so on, but totally barbarian in the social way. There is a special (and only) way to identify two groups of creatures by pointing a little device on the person, orange light - "Chatlanian" (superior), green - "Patsak" (lower class). The most valued things on the planet are matches (or, rather, the chemicals ordinarily used on Earth for match heads). One match head equals to 2200 "chatles". Uncle Vova and Gedevan "the Fiddler" Alexidze, have a long and dangerous journey in order to get home...