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