Here is the full list of all 84 OMORI achievements. It takes around 80-100 hours to unlock all of the achievements on Windows.
Take the KEEPER OF THE CASTLE's power.
Unlock all achievements. Thank you for playing OMORI.
Complete the FOE FACTS! journal.
Defeat every SOMETHING at the bottom of the LOST LIBRARY.
Look through all telescopes.
Get all rewards from the RECYCLING MACHINE.
Recover at all of MARI's picnics.
Visit all mirrors.
Beat the BOSS RUSH.
Commission all of GATOR GUY's statues.
Commission all of ROCOCO's art.
Defeat PERFECTHEART.
Defeat MUTANTHEART.
Defeat ROBOHEART.
Watch all movies in SWEETHEART'S "throne room".
Defeat SPACE EX-HUSBAND.
Let the plastic fish finish its song.
Defeat PLUTO and THE EARTH.
Defeat 100 BUNNIES.
Read all the tombstones in the... dev room...
Pet all the creatures in MARINA's sector in HUMPHREY.
Hold 99 TOFU.
Trade CLAMS for CLEMS.
Defeat UNBREAD TWINS.
Get the LOL SWORD.
Turn the valve to the right in RAIN TOWN.
Defeat the CHICKEN? at the top of DINO'S DIG.
Complete ORANGE JOE's quest.
Defeat 100 SQUIZZARDS.
Reach the other ending.
Defeat the PET ROCK champion.
Defeat the RECYCLEPATH.
Receive all FLOWERS in the hospital.
Go to SEAN and KAREN's housewarming party.
Throw away something.
Insert every song into GINO'S JUKEBOX.
Feed the STRAY CAT every day and sunset.
Give FLOWERS to MARI.
Brush your teeth every day.
Defeat the HOOLIGANS with PEPPER SPRAY.
Battle the "bees".
Take $20.00 from KEL's wardrobe.
Don't high-five KEL.
Lose to KIM and VANCE.
Complete the grammar worksheet correctly.
Complete the math worksheet correctly.
Get a perfect score delivering PIZZA.
Complete all part-time jobs once.
Quit in the middle of a part-time job.
Get the FLOWER CROWN from BASIL.
Complete your TO-DO LIST.
Have a ghost party.
Commission ROCOCO.
Gain BREAD using BREAD SLICE.
Choose the SUMMER MOLE.
Choose the SPRING MOLE.
Choose the WINTER MOLE.
Choose the FALL MOLE.
Listen to MR. SCARETHROW's rant.
Enter code: haveadollariguess at www.omocat-shop.com for $1.00 off.
Reach the bad ending.
Reach the good ending.
High-five KEL three times.
Defeat KITE KID.
Defeat HUMPHREY.
Defeat SLIME GIRLS.
Defeat PLUTO (EXPANDED).
Defeat MR. JAWSUM.
Defeat SWEETHEART.
Perfectly train the SPROUT MOLE choir.
Kill the first SOUS CHEF.
Ruin Christmas.
Go to sleep after a long day.
High-five KEL.
Wake up in the morning.
Make your way and talk to LONE MOLE.
Defeat SPACE EX-BOYFRIEND.
RELEASE ENERGY on your foes.
Defeat DOWNLOAD WINDOW.
Defeat THE EARTH.
Defeat ???.
Fly the BUTT CERTIFICATE in CATTAIL FIELD.
Pet a dog.
Water a plant back to life in BASIL's garden.