Here is the full list of all 121 The Madness of Little Emma achievements.
Kill Manless Face as Amelia
Complete episode 2 without collecting hearts and healing herbs
Unlock fifth ending
Complete episode 4 without collecting hearts and healing herbs
Unlock sixth ending
Complete Arena as Amelia
Complete Arena as Marah
Complete Arena as Chloe
Complete Arena as Lucretia
Complete Arena as Elizabeth
Complete episode 1 without collecting hearts and healing herbs
Unlock Chloe
Complete Arena as Emma
Complete Arena
Get very unlucky
Unlock final ending
Kill all bosses in episode 4
Kill Spirit
Unlock Marah
Unlock third ending
Kill April
Unlock second ending
Get really insane!
Get very lucky
Kill Eidolon
Kill a shopkeeper
Reach The Riddle
Kill all bosses in episode 3
Kill Meat Bag
Kill 4 Seasons
Kill Autumn
Buy 5 items in one playthrough
Destroy a turnip
Kill Summer
Kill Winter
Kill Spring
Have only 1 heart container
Unlock first ending
Kill Manless Face
Kill Sinister Mask
Kill Haunt
Kill all bosses in episode 1
Unlock Lucretia
Kill Entozoon
Kill all bosses in episode 2
Find a red chest
Reach Misery
Kill the fat man
Kill Red Viper
Reach Undergrounds
Unlock Amelia
Find Love Burrow
Kill Alice
Reach Den
Kill Mask
Find a secret
Unlock Elizabeth
Kill Liquid Sisters
Collect 5 health bonuses in one game
Kill a boss
Kill Green Viper
Die
Find everything
Complete ending 4 with clean mind all the time
Unlock every other achievement
Complete episode 3 without collecting hearts and healing herbs
Find all Love Items