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