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