Here is the full list of all 84 OMORI achievements. It takes around 80-100 hours to unlock all of the achievements on Windows.
Reach the other ending.
Unlock all achievements. Thank you for playing OMORI.
Receive all FLOWERS in the hospital.
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.
Complete the grammar worksheet correctly.
Complete the math worksheet correctly.
Complete all part-time jobs once.
Defeat the PET ROCK champion.
Lose to KIM and VANCE.
Get a perfect score delivering PIZZA.
Quit in the middle of a part-time job.
Beat the BOSS RUSH.
Defeat PERFECTHEART.
Complete the FOE FACTS! journal.
Defeat ROBOHEART.
Defeat MUTANTHEART.
Take the KEEPER OF THE CASTLE's power.
Defeat every SOMETHING at the bottom of the LOST LIBRARY.
Defeat SPACE EX-HUSBAND.
Recover at all of MARI's picnics.
Look through all telescopes.
Visit all mirrors.
Let the plastic fish finish its song.
Defeat PLUTO and THE EARTH.
Commission all of GATOR GUY's statues.
Get the FLOWER CROWN from BASIL.
Complete your TO-DO LIST.
Read all the tombstones in the... dev room...
Pet all the creatures in MARINA's sector in HUMPHREY.
Get the LOL SWORD.
Have a ghost party.
Defeat 100 BUNNIES.
Commission all of ROCOCO's art.
Commission ROCOCO.
Defeat 100 SQUIZZARDS.
Turn the valve to the right in RAIN TOWN.
Defeat UNBREAD TWINS.
Defeat the CHICKEN? at the top of DINO'S DIG.
Complete ORANGE JOE's quest.
Trade CLAMS for CLEMS.
Watch all movies in SWEETHEART'S "throne room".
Hold 99 TOFU.
Choose the SPRING MOLE.
Choose the SUMMER MOLE.
Choose the FALL MOLE.
Get all rewards from the RECYCLING MACHINE.
Listen to MR. SCARETHROW's rant.
Defeat ???.
Make your way and talk to LONE MOLE.
Fly the BUTT CERTIFICATE in CATTAIL FIELD.
Throw away something.
Enter code: haveadollariguess at www.omocat-shop.com for $1.00 off.
Reach the bad ending.
Reach the good ending.
Give FLOWERS to MARI.
High-five KEL three times.
Defeat KITE KID.
Defeat HUMPHREY.
Defeat SLIME GIRLS.
Defeat PLUTO (EXPANDED).
Defeat MR. JAWSUM.
Defeat SWEETHEART.
Kill the first SOUS CHEF.
Perfectly train the SPROUT MOLE choir.
Ruin Christmas.
Choose the WINTER MOLE.
Go to sleep after a long day.
High-five KEL.
Pet a dog.
Wake up in the morning.
Defeat THE EARTH.
Defeat SPACE EX-BOYFRIEND.
RELEASE ENERGY on your foes.
Defeat DOWNLOAD WINDOW.
Gain BREAD using BREAD SLICE.
Water a plant back to life in BASIL's garden.