Here is the full list of all 66 Evil Heart Fever achievements.
Initial Form
Demon Form
Metal Form
Ancient Form
Plague Form
Cyber Form
More movement speed
More range
More shot speed
More fire rate
Dash loads faster
One more heart
More range and wisdom, less speed
More speed and damage, less range and wisdom
More damage and dash, less range and wisdom
More damage, less range
More damage, less wisdom
More speed and dash, less wisdom
More fire rate, less speed
More damage, less life
Bad habits
Life up, speed down
Range up, wisdom down
Damage, shotspeed and range, wisdom down
Range, wisdom down
Wisdom up, speed down
Sodom and Gomorrah
Great Cthulhu inside me
The clamping force
The present is theirs; the future, for which I really worked, is mine
Cut it all
Tadpole Missiles
Dengue, Chikungunya, Zika
Infernal Feelings P.I
Infernal Feelings P.II
Infernal Feelings P.III
One in all and all in one
Dash saw cut
Death is part of life
Very dangerous
Laser weapon system
Bot Mines system
Meet and kill Cherub
Meet and kill Baby Blue Cherub
Meet and Kill Light Red Cherub
Meet and Kill Archer Cherub
Meet and Kill Blue Cherub
Meet and Kill Red Cherub
Meet and Kill Purple Archer Cherub
Meet and Kill Smurt Cherub
Meet and Kill Rage Cherub
Meet and Kill Gamma Ray Cherub
Meet and Kill Silver Cherub
Meet and Kill Gold Cherub
Meet and Kill Super Cherub
Meet and Kill Seraph
Meet and Kill Throne
Meet and Kill Dominion
Meet and Kill Virtue
Meet and Kill Power
Meet and Kill Principality
Meet and Kill Archangel
Meet and Kill Angel
10% Open
50%
100% Hell