Here is the full list of all 49 Atelier Ryza: Ever Darkness the Secret Hideout achievements.
Earned all trophies.
Created an item with Item Level 99.
Got Ryza's alchemy level to 99.
Obtained all recipes.
Created a bottle with Gathering Synthesizer Level 51.
Defeated the Queen of Shadows.
Became a Braver.
Defeated all 5 Great Elements.
Saw everyone move on to chase their dreams.
Created the Crimson Stone and saved Kurken Island.
Wrote a record of every exploration.
Defeated the Queen of Darkness.
Got Ryza's battle level to 50.
Defeated the King of Storms.
Obtained the Revelation Book.
Defeated the Eternal Sculpture.
Defeated the Mirage Master.
Defeated the Savage Assassin.
Found and installed all Power Reactors.
Defeated the Noble Paladin.
Completed requests to get Peter to interview you.
Found all treasure chests.
Activated everyone's Fatal Drive.
Defeated the Shining Puni.
Entered the Kurken Bunker.
Saved the goat you met on your travels.
Helped create Rasen Pudding.
Visited the Holy Tower of Pynnor and learn the truth.
Created the Bomb Rod.
Installed the Multiplicauldron at the secret hideout.
Helped Empel regain his former strength.
Spent the night camping in the Underworld.
Laid eyes on the Underworld.
Installed the Gathering Synthesizer at the secret hideout.
Learned about the history of Ryza and the others.
Created the Bug Net.
Installed a Power Reactor at the secret hideout.
Defeated the dragon at the old castle.
Found one treasure chest.
Created the Hammer.
Created the Fishing Rod.
Wrote a record of one exploration.
Built a secret hideout for everyone.
Witnessed the rise of a strange beast.
Attended a tea party with Ryza and Klaudia.
Created the Woodcutter's Axe.
Created the Reaper's Scythe.
Synthesized for the first time.
Visited the mainland for the first time.