There are some intriguing mysteries hidden in here, but I either haven't figured out how to access them or I haven't gotten lucky enough with potion generation.
I'm pretty sure that the highest mercury level I've hit is the one after "looming," which seems to be connected to the confetti related disappearances, but I don't think I've met a wizard, and I'm not sure how the rat factors in.
Unfortunately, whenever I get to that level of mercury, the game closes on the next card. (Maybe Unity died of mercury poisoning?) see edit.
Oh! Also, adding the "transformation" tag to this will make it a lot easier for people browsing Itch to find.
Edit: OH. I see. Well, I don't think it even displays for a frame before closing, but, uh, yeah, I see what's going on now, haha. Well, that was definitely fun to find.
Same goes for the "visited every card by cheating" message, though I still haven't been able to trigger the secret ending, (it's plush + bunny + has plush + encounter girl, right?) and I have zero clue what the secret button on the main menu does beyond turn purple, haha.