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