I first learned of Quentin Dupieux when I saw his 2010 absurdist black comedy "Rubber" (about a tire on a killing spree). Now comes "Réalité" ("Reality" in English), about a director who has to find the ideal groan of pain for a proposed movie. At least that's the main plot. Throughout the movie, reality, fiction and dreams keep overlapping so that you're not sure just what is real. David Lynch's "Mulholland Drive" is probably the only other movie that messes with your mind this much.
This movie won't be for everyone. You have to be willing to accept the repeated shift from apparent reality to fiction, often taking place simultaneously. Assuming that you enjoy a movie that deliberately confuses you, you'll like this one. It's not like anything that you've ever seen.
PS: Quentin Dupieux is an electronic musician who goes by Mr. Oizo (a corruption of the French word for bird).