If you loved The Flat, try Virile Games
A bridge between a film you've already seen and one most people haven't. Here's what they share, and what the second one does that the first one doesn't.
What they share
Both films are directed by Jan Švankmajer, and they both carry the surreal mood tag, and they sit in Animation / Horror territory. If that's the register that drew you to The Flat, the second film will land in a comparable space — through a different lens.
surreal
What Virile Games is
Autumn afternoon. A cracked TV flickers in a dim apartment. Men in kits hack and saw at each other on the pitch, limbs splintering like dry branches. The screen ruptures when they crawl out, still kicking. Feels like a VHS tape rotting in real time.

