The feel
Recognition, not speed.
The puzzle is not “which words are similar?” It is “what relationship repeats across these pairs?”
Four sets, four difficulty tiers, revealed on solve and never shown on the live board: difficulty is discovered, not warned about.
GREENYELLOW
REDBLACK
Cozy is a constraint, not a mood. No timers, no confetti, no particles. Mistake pips are coffee beans and never red. Lose on the fourth mistake and the loss screen reveals every unsolved set with its explanation, so you always find out what you missed.
I declared the taste bar on day one, not once the pipeline made it necessary: it is not enough for a set to be valid, it has to feel like something. That standard has a name later in this deck, and a machine gets graded against it.
This deck is how ASTO was made. The game design document (v0.13, living) is what it was meant to be. They are companion reads.