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.
Activated everyone's Fatal Drive.
Obtained all recipes.
Defeated all 5 Great Elements.
Created a bottle with Gathering Synthesizer Level 51.
Wrote a record of every exploration.
Saw everyone move on to chase their dreams.
Created the Crimson Stone and saved Kurken Island.
Defeated the Queen of Darkness.
Got Ryza's battle level to 50.
Entered the Kurken Bunker.
Defeated the Eternal Sculpture.
Obtained the Revelation Book.
Defeated the Mirage Master.
Completed requests to get Peter to interview you.
Found all treasure chests.
Found and installed all Power Reactors.
Created the Fishing Rod.
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 King of Storms.
Defeated the Savage Assassin.
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 Hammer.
Installed a Power Reactor at the secret hideout.
Defeated the dragon at the old castle.
Created the Bug Net.
Found one treasure chest.
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.