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