Here is the full list of all 48 Kraken Academy!! achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Beat Yuki and Wendy's challenges on hard.
Save Kraken Academy from doom and destruction.
Free the Drama Club spirit.
Complete all side quests.
Befriend the Janitor.
Collect 75,000 shlotinki.
Collect all furniture.
Befriend Kostadin.
Befriend the Hobo Guy.
Befriend Jean.
Befriend Pierre.
Dig up all piles of dirt in one time loop.
Collect all club cards.
Free the Sports Club spirit.
Pull all the levers in the boss's office.
Get the drama club uniform.
Smash 1000 things.
Get a score of 20 or more in Dimitri's challenge.
Go on all the dates.
Befriend Vladimir.
Befriend Nikolai.
Befriend the Cafeteria Lord.
Summon a poop demon.
Befriend Patitsa.
Befriend Ana.
Befriend Dimitri.
Score a goal in the gym.
Free the Art Club spirit.
Befriend Broccoli Girl.
Befriend Ms. Markova.
Befriend Simona.
Put furniture into every slot in your room.
Get the cultist robes.
Collect 10,000 shlotinki.
Collect 175 bottles in one go.
Convert 3 bottlemachines to the cause in one time loop.
Free the Music Club spirit.
Get the skeleboner costume.
Bounce on a bouncy castle.
Wash your hands in 4 different sinks.
Smash 250 things.
Pet a cat.
Witness the end of the world.
Get the penguin costume.
Call your Mom 8 times.
Travel back to Monday 5 times.
Gain the power to travel back in time.
Collect 75 bottles in one go.