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