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