Here is the full list of all 42 PANIC at Multiverse High achievements.
Enjoyed the spooky activities of Halloween!
Made it through the boringness of Surrender Day!
You've earned the true friendship of Amunet-Ana!
You've earned the true friendship of Baby!
You've earned the true friendship of Captain Cascadia!
You've earned the true friendship of Click!
You've earned the true friendship of Cold Snap!
You've earned the true friendship of Cupcake!
You've earned the true friendship of Getz!
You've earned the true friendship of Kablam-O!
You've earned the true friendship of Lug!
You've earned the true friendship of Mambanaga!
You've earned the true friendship of MagiGator!
You've earned the true friendship of Pangari!
You've earned the true friendship of Rabbit!
You've earned the true friendship of Savi!
You've earned the true friendship of Remix!
You've earned the true friendship of Slick Anger!
You've earned the true friendship of Staterius!
You've earned the true friendship of Vinka Bloom!
You've gone and fallen for... CHAD?! WTF?
Maxed out your Tough attribute.
Maxed out your Nice attribute.
Maxed out your Cool attribute.
Beat the game!
Get close to any character.
Destroy a friendship with (certain) characters.
Get a perfect GPA.
Get the secret ending FOR REAL!
Complete Art Club.
Complete Drama Club.
Complete Magic Club.
Complete Music Club.
Complete Study Hall.
Complete Sports Club.
Celebrate the bounty of the Harvest Festival.
Get presents from the Bearded Yulenchilde.
Resolve the threat of the Groundhog Demon
Train your Leafee into fighting shape!
Obtained all the achievements!
Participated in the events of Valentine's Day!
Took part in the activities of Arts Day!