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