Here is the full list of all 52 Lone Fungus achievements.
Fullfill your destiny on the 'Nightmare' Difficulty (True Ending)
Achieve 100% completion and finish the game on the 'Nightmare' Difficulty (True Ending)
Fullfill your destiny on the 'Hardcore' Difficulty (True Ending)
Achieve 100% completion and finish the game (True Ending)
Parry 200 Projectiles
Collect all Relics
Learn everything you can from the Grand Librarian
Collect all Astral Fragments
Unlock all Bounce abilities
Read all the 'Ten Commandments' tablets
Open all levered one way gates
Collect 75 Mindshrooms
Listen what the Professor Statue has to say about each mushroom cap
Fully upgrade your sword's damage
Collect all Health Crystals
Cut 1000 Flowers/Flora
Collect all Ladybugs
Talk to every Major Statue
Fullfill your destiny on the 'Normal' Difficulty (True Ending)
Unlock the Royal Ornament
Collect all Emblems
Acquire the Spark Ball Spell
Leave the Kingdom (Abandonment Ending)
Complete the game (True Ending / Selfish Ending)
Forget the past, reincarnate only the Greencap culture of mushrooms (Selfish Ending)
Learn both Great Slashes
Collect all Brain Nodes
Collect 50 Mindshrooms
Use the Bouncy Spore Spell to reach somewhere higher up
Downward Slash the Bouncy Spore 5 times in a row without touching the ground
Acquire the Returning Contraption Spell
Collect all Spell Stones
Unlock the Teleportation Wand
Unlock the Crouch Jump ability
Acquire the Golden Light Spell
Acquire the Vibrant Crystal Spell
Unlock the Fire Bounce ability
Acquire the Spicy Nut Spell
Unlock the Spin Jump
Acquire the Bouncy Ball Spell
Collect 4 Health Crystals
Collect 25 Mindshrooms
Defeat 500 Enemies
Acquire the Berserk Spell
Unlock the Wall-Bounce ability
Acquire the Acid Hammer Spell
Acquire the Boost Projectile Spell
Acquire the Bouncy Spore Spell
Unlock both the Dashes
Defeat 100 Enemies
Learn how to Conjure a Mushmover
Unlock the Mushmover Infusion ability