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