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