Here is the full list of all 44 Nefarious achievements.
Get the good ending.
Put your friendships before your ambitions.
Witness Dr.Cackle being arrested.
Tell Mayapple not to drop Dr. Cackle in his Lab.
Find all three mutant Farrah Days
Get the bad ending.
Listened to the heroes entire motivational speech at Bramble flats.
Defeat 100 enemies with punches.
Beat any stage by only punching, without firing a single long ranged weapon.
Defeat the Treble Rangers at the Villain Museum.
Found the hidden monster at the villain museum.
Read all of the portrait descriptions of Crow's Lineage in his wing at the Villain Museum.
Witness the might and fury of Monster-Farrah.
You have appeared on the dating game "Would You Date a Super Villain?"
Have the audience choose Crow to date Becky in "Would You Date A Supervillain?"
Unlock Farrah's Folly.
Defeat Mack at Adept Co. without getting hit once.
Defeat 100 enemies with grenades.
Counting any amount spent, gather a grand total of 10,000 lucre.
Defeat 50 enemies with grenades.
Defeat 50 enemies with punches.
Defeat 20 enemies with grenades.
As a result of being defeated, dropped a princess.
Defeat 20 enemies with punches.
Hit the swat van with one of it's own bazooka blasts.
Beat Dash in Insektia without taking any damage.
Defeat Mechano using only his own missiles.
Get the first crown in Sukochi.
See all the dialogue scenes in Heartless Abyss.
Complete Rattletrack Rails without dying.
Drop the kingdom's assembled defenders into the lava pool at Crow's Fortress in Bramble Flats.
Unlock all the music for the Jukebox.
Find all the crowns in the game.
Unlock all upgrades, view all endings, find all the vinyls, and collect all the crowns in the game.
Had a long conversation with your upgrade station S.T.A.B.I.L.E
Read all 16 terminals in Adept Co. and discover who funded the sinister organization.
Achieve S-Ranks on all stages.
Sacrificed friendship to achieve your cruel ambitions.
Honored the terms of your dark pact with Kaptain Man.
Buy every upgrade in the upgrade shop.
Beat the game without buying a single upgrade.
Defeat Guryon in Winterdown without getting hit once.
Beat the game having collected less than 1,000 lucre.
Beat Dash, Guryon and the 8-bit heroes without dying or taking damage at the Bramble Flats.