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.
Became a Braver.
Obtained all recipes.
Obtained the Revelation Book.
Completed requests to get Peter to interview you.
Defeated the Mirage Master.
Found all treasure chests.
Defeated the Queen of Shadows.
Activated everyone's Fatal Drive.
Wrote a record of every exploration.
Created a bottle with Gathering Synthesizer Level 51.
Got Ryza's battle level to 50.
Defeated all 5 Great Elements.
Helped create Rasen Pudding.
Saved the goat you met on your travels.
Saw everyone move on to chase their dreams.
Created the Crimson Stone and saved Kurken Island.
Defeated the Queen of Darkness.
Defeated the King of Storms.
Defeated the Savage Assassin.
Entered the Kurken Bunker.
Found and installed all Power Reactors.
Visited the Holy Tower of Pynnor and learn the truth.
Defeated the Noble Paladin.
Created the Bomb Rod.
Installed the Multiplicauldron at the secret hideout.
Found one treasure chest.
Defeated the Eternal Sculpture.
Defeated the Shining Puni.
Helped Empel regain his former strength.
Installed the Gathering Synthesizer at the secret hideout.
Spent the night camping in the Underworld.
Learned about the history of Ryza and the others.
Laid eyes on the Underworld.
Created the Bug Net.
Wrote a record of one exploration.
Created the Hammer.
Installed a Power Reactor at the secret hideout.
Defeated the dragon at the old castle.
Created the Fishing Rod.
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.