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