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