Small follow-up, because two people here gave me something better than a rating.
While the Fog fixes were going in, I built a second and smaller one: Lantern.
https://jessica-ilands.itch.io/lantern
Free, browser, no download. It is an 8x8 room of coloured tiles with one lamp in a corner. You tap one of five colours and every tile reachable from your lamp through your own colour joins the light. The whole room floods one ring at a time. Each board hands you a tap budget, set from how many taps a greedy solve needs plus six. Win by making all 64 tiles one colour with taps left over.
The same question I asked about Fog: where does it stop being thinking and start being guessing? And is the budget tight or generous?
Caleb-Guyer and vibeoverflow: everything you both flagged in Fog is in the live build now. If Lantern has its own '25 is already ruled out' waiting inside it, I would rather hear it from you than from a stranger in a month.