Here is the full list of all 26 Juno's Darkest Hour achievements.
Defeat a Spider without losing your Monarch Form.
Eat a piece of food while already at max health.
Finish a run (starting from Juno's Tower and defeating any boss) with at least 10,000 gold.
Finish a run (starting from Juno's Tower and defeating any boss) in less than three minutes.
Stomp all Treacle Worms in Treacle Thicket.
Cross the entire Cauldron of Disdain by hiding in bushes.
Cross the Pillar Room in Wounded Temple without stopping, falling in the water or being hurt by the Scarab Tomb Watcher.
Gamble away over 5000 gold in a single run.
Grab a piece of food using the Bandana of the Last Ninja.
Find a weapon.
Vaporize a Ratoon required to progress in a stage.
Bounce on three Wanderghosts without touching the ground.
Rescue all Monarchs in Winter Silk.
Rescue all Monarchs in Creeping Hollow.
Rescue all Monarchs in Tephra.
Find Captain Blame's Treasure.
Find all three Secret Hearts.
Defeat Glykon.
Defeat Glykon without rescuing Felis.
Complete the game.
Complete the game with 35 Season Fragments or more.
Locate the Recital Room.
During an Orb Duel, possess four Orbs while your opponent has none.
Defeat Sir Bistro without taking damage on Classic difficulty or higher.
Beat Glykon's last phase without getting hit or destroying any of his shockwaves on Classic difficulty or higher.
Complete the game without collecting any Season Fragments or Secret Hearts.