Here is the full list of all 49 Atelier Ryza: Ever Darkness the Secret Hideout achievements.
Earned all trophies.
Obtained all recipes.
Became a Braver.
Created an item with Item Level 99.
Created a bottle with Gathering Synthesizer Level 51.
Obtained the Revelation Book.
Completed requests to get Peter to interview you.
Found all treasure chests.
Defeated the Queen of Shadows.
Got Ryza's battle level to 50.
Defeated all 5 Great Elements.
Defeated the Eternal Sculpture.
Defeated the King of Storms.
Defeated the Mirage Master.
Defeated the Savage Assassin.
Got Ryza's alchemy level to 99.
Wrote a record of every exploration.
Saw everyone move on to chase their dreams.
Activated everyone's Fatal Drive.
Created the Crimson Stone and saved Kurken Island.
Defeated the Queen of Darkness.
Entered the Kurken Bunker.
Saved the goat you met on your travels.
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.
Defeated the Shining Puni.
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.
Helped create Rasen Pudding.
Found one treasure chest.
Created the Bug Net.
Installed a Power Reactor at the secret hideout.
Defeated the dragon at the old castle.
Wrote a record of one exploration.
Created the Hammer.
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.