A few things I've noticed with puzzles:
Possible non-issue that will be fixed as the UI changes - Blue completion flags only appear after returning to the kingdom screen and re-entering the Explorers' Guild, after you finish a puzzle and return to the menu it is not yet marked complete.
The goat at the end of the first tutorial dungeon doesn't actually deal enough damage to kill you. After you find the final sign, it changes its combat prediction from the entertaining "talk" to "safe".
Irrelevant style detail that has been bugging me for 18 months - The powerups tutorial describes Arcane Amplifiers as useful for "alliterative endeavours". Surely this could be "alliterative activities".
(Cue debate about alliteration vs assonance).
The signs that spawn after repeated death in Halfling Puzzles 1, 2 and 3 ("Intro to Halflings", "Halfling Trial" and "Ring o Death") have no text. The gnome puzzle hints work fine.