Can't the event achivements just be made so they don't count to that 100% of achivements. And put them at the bottom wit the note special achivent or legendary achivements?
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And i can tell you avfew that sure work:
Eroil icecream, hector relax, pet rock, cucumbers
All betls work
All full sets work but there is no full vortex and magma achivement
500 acids bloods is from another world
ranking achivements don't work (look at rank 1 and see they don't have it)