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 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.
Created an item with Item Level 99.
Got Ryza's alchemy level to 99.
Became a Braver.
Obtained all recipes.
Wrote a record of every exploration.
Defeated the Queen of Darkness.
Obtained the Revelation Book.
Completed requests to get Peter to interview you.
Defeated the Savage Assassin.
Found all treasure chests.
Activated everyone's Fatal Drive.
Defeated the Noble Paladin.
Got Ryza's battle level to 50.
Found and installed all Power Reactors.
Defeated the King of Storms.
Helped create Rasen Pudding.
Entered the Kurken Bunker.
Defeated the Mirage Master.
Created the Bomb Rod.
Installed the Multiplicauldron at the secret hideout.
Visited the Holy Tower of Pynnor and learn the truth.
Defeated the Eternal Sculpture.
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.
Laid eyes on the Underworld.
Created the Bug Net.
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 Hammer.
Created the Fishing Rod.
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.