Fantastic puzzle book! As a newbie to the genre (and someone who really struggled with some of the other rule-discovery games you mentioned) I found this to be very accessible and enjoyable as a result. I’d highly recommend this to others.

Heavy spoilers below (rot13):

V fghzoyrq hcba “GUR” ehyr jura erivrjvat gur pbaprcgf cntr gb svther bhg jung V jnf zvffvat gb fbyir chmmyr #9. V gubhtug “uhu, gung’f n jrveq pbvapvqrapr” naq gura vg qnjarq ba zr. Fhqqrayl gur gvgyr znqr frafr gbb. Jung na rkpryyrag n-un zbzrag!

Urer’f zl vagrecergngvba bs gur ehyrf.

• Qenj n yvar sebz rirel fgneg (oynpx pvepyr) gb raq (juvgr pvepyr).

• Gur yvar zhfg ivfvg rirel fdhner jvgu n oynpx gevnatyr

• Gur yvar zhfg nibvq rirel fdhner jvgu n juvgr gevnatyr

• Gur yvar zhfg pebff bire rirel oynpx oevqtr

• Gur yvar zhfg nibvq pebffvat bire nal juvgr oevqtr

• Gur yratgu bs gur yvar zhfg rdhny a+1, jurer a vf gur chmmyr ahzore.

P.S. The spilled paint reminded me of a similar pdf puzzle called ‘Letter Coins’ if you haven’t tried that yet.

I tried this after seeing it in a youtube comment and it was a good short fun time. It's really interesting to solve a puzzle where you need to figure out the restrictions based on context.

surprisingly intuitive rule discovery puzzle book, hats off to the creator

Nice puzzle design! I solved the first 18 puzzles. Is 19 a puzzle?