Wow, this is a lively one. I really enjoyed the menacing music and the slightly unhinged visuals. I didn't even realise I'd lost the first time because the gameplay continues despite the game over message being visible, an interesting design decision! Very nice game
The tiles wound up with a Windows 95 shareware vibe because the CGA text-mode hack for 16-color graphics made some shapes impossible. Triangle up: trivial. Triangle down: gave up and drew an urn.
Gameplay after failure is part of the game being ephemeral. There's no high score table. There's no ending. It just ramps up to barely-tolerable pressure and stays there. The only difference after topping out is the lack of screen clears, because scoring stops.
Difficulty is the same past level 0x10. There's a way to score high enough, on the first screen, to go straight there.