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