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