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