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.
Obtained all recipes.
Obtained the Revelation Book.
Wrote a record of every exploration.
Defeated the Queen of Darkness.
Got Ryza's battle level to 50.
Completed requests to get Peter to interview you.
Became a Braver.
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.
Defeated the King of Storms.
Saved the goat you met on your travels.
Activated everyone's Fatal Drive.
Created the Bomb Rod.
Installed the Multiplicauldron at the secret hideout.
Defeated the Mirage Master.
Defeated the Eternal Sculpture.
Defeated the Savage Assassin.
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 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.