Here is the full list of all 46 Ys Origin achievements.
Complete Boss Rush on Normal difficulty with any character.
As Hugo, obtain ultimate power... then let it go to waste completely.
Complete any Arena stage with less than 10 HP.
As Yunica, persevere against an unbeatable foe in the Guilty Fire.
Unlock every character's EX version.
Purchase everything available in the Bonus Shop.
Spend more than 2,000,000 SP in the Bonus Shop.
Unlock any character's EX version.
Complete Boss Rush on Easy difficulty with any character.
Unlock Adol the Red in the Bonus Shop.
Defeat the final boss and obtain the game's true ending.
When playing as neither Yunica nor Hugo, completely refrain from using Burst until the final encounter.
Defeat the Demonic Core end boss with all playable characters.
As Hugo, defeat Toal; as Toal, defeat Hugo.
Obtain all blessings/upgrades with all characters.
Defeat the mid-boss in the Hall of Reflection with all playable characters.
Give Roda Fruit to all of the Roos in the tower with every character.
Defeat the Blighted Blood end boss with all playable characters.
Defeat the Silent Sands end boss with all playable characters.
Defeat the Guilty Fire end boss with all playable characters.
Defeat the Flooded Prison end boss with all playable characters.
Defeat the Wailing Blue end boss with all playable characters.
Complete the game as Hugo.
Thwart the Darkling lackeys in the Demonic Core as both Yunica and Hugo.
Defeat the mid-boss in Rado's Annex as both Yunica and Hugo.
Fight all enemies (excluding bosses) enough times to fill in all blank data entries for them in your monster journal.
As Hugo, emerge victorious during your emotional encounter in the Guilty Fire.
Thwart Epona's early-game challenges as both Yunica and Hugo.
Enable "No-Fall" mode for the first time.
Complete the game as Yunica.
Unlock Toal by completing the game as Yunica or Hugo.
Complete the game on Very Easy difficulty with any character.
Complete the game on Easy difficulty with any character.
Complete the game on Normal difficulty with any character.
Obtain all blessings/upgrades with any character.
Purchase your first blessing/upgrade.
Fight and defeat Pikkardon in Arena Mode.
Complete four or more consecutive stages in Arena Mode without taking any damage.
Complete the game on Hard difficulty with any character.
Complete the game on Nightmare difficulty with any character.
Complete the game on Nightmare difficulty with all characters.
Complete Boss Rush on Hard difficulty with any character.
Complete Boss Rush on Nightmare difficulty with any character.
Complete Boss Rush on Nightmare difficulty with all versions of all characters.
Unlock Yunica's schoolgirl outfit.
Unlock all other achievements.