Here is the full list of all 30 LiEat achievements. It takes around 5-6 hours to unlock all of the achievements on Windows.
Play Liar (music track) at the Slowest Speed in Post-game
Get Bad Ending from Losing Boss Battle
Get Bad Ending from Wolf Encounter
Defeat a Red Moth
Put Panties on your Head
Eat 15 Cookies
Good Ending
Neutral Ending
Bad Ending
Pair up with Iris
Pair up with Neil
Pair up with Brett
Sleep in the Bed During the Maid Investigation
Find the Legendary Knife and Cookie
Have Iris Analyze You
Find the Funny Glasses
Bad Ending, Lose to William
Find the Cherry Candy in the Trash
Poke Efi Three Times While Sleeping
Fight Three Blue Rats
Fight the Girlfriend Lie
Fight the "I'm not drunk!" Lie
Rest Two Times in a Row
Find out about Hal's Cracked Phone
Steal the Money from the Bookshelf
Finish LiEat 1
Get Efi to Level 10
Steal the Candy from Keith and Rachel's House
Find Big Liar Equipment