I got all the stones (including elusive zero) and am now curious, what’s the third difficulty option that gets blanked out? And what’s the meaning of “will you discover the █̸̟̘̜̑̏u̴͍̐̊█̸͕̆l̸̡̝͈͗s̵̩̩͊̇̈█̷͍̰̇͛█̷̧̰́ņ̶̣͇͐̃͠█̵̺͕͊̅͑ ?” I tried replacing those blanks (?u?ls??n?), but doesn’t seem there’s any word matching that pattern. I feel like there’s still some super duper secret I’m missing… I did notice that my winning deck against the first tutorial dude is supposedly this:

But there’s no way that I had 59-stone in my deck when I beat them and actually the icon shown there isn’t the same as 59-stone so idk. I don’t recognise ever using a deck like that, and I can’t replicate it without knowing what that mysterious ghost + black stone is. Could I get a pointer please?

Eureka -- I figured out the weird sprite! Even though it's an old version of 59, it's also used in the game as 65-stone. You used 65- and 5-stone in your deck to solve a puzzle, then went back to beat the tutorial. No glitch involved!

[I somehow missed this when looking at the spritesheet, I only noticed when watching the posted video where the player accidentally made 65 while deckbuilding!]