Sasha Sienna of MacGuffin & Co. made this wonderfully cheeky one-page DUNE role-playing game, which they describe as "The 'extremely official' 'game' for 'people' who have definitely 'read and understood' the book(s?)."
It is simple, comprehensive, and hilariously accurate.
The slightly-more designed version of the game (with typos corrected) expands it to a whopping two pages, but is otherwise identical:
There's also an accessible / screen-friendly text-only version that expands the same rules to … 4 pages. Very complex, yet still accessible!
MacGuffin & Co makes all kinds of fun one-page RPGs; you can access them all via Patreon. Or, if you're interested in a more complicated Dune RPG — which is kinda weird, to be honest, but hey, you do you — there's one from Modiphius Entertainment called Adventures in the Imperium that has an 82-page rulebook and uses a D20 system. And don't forget that Dune Collectible Card Game either!
Planet Dune: The "extremely official" "game" for "people" who have definitely "read and understood" the book(s?) [Sasha Sienna / MacGuffin & Co.]