Here is the full list of all 37 Timespinner achievements. It takes around 12-15 hours to unlock all of the achievements on Windows.
Achieve all possible feats on the same save file.
Prevent the Qaelans from being persecuted by the Empire.
Beat the game on Nightmare mode.
End the War of Sisters before any blood is shed.
Defeat Nightmare in battle. (Normal or Nightmare mode only)
Defeat the Sandman in battle. (Normal or Nightmare mode only)
Discover 100% of the map.
Acquire every Orb Spell.
Acquire every Orb Passive.
Collect all Familiar companions.
Have an Alchemist make you a new Passive ring.
Find all Melee Orbs.
Defeat the Ravenlord in battle. (Normal or Nightmare mode only)
Defeat Ifrit in battle. (Normal or Nightmare mode only)
Defeat a boss without stopping time nor taking damage.
Defeat the ruler of Lachiem.
Defeat Emperor Nuvius in battle. (Normal or Nightmare mode only)
Finish all character quests.
Collect all Memories.
Collect all Memories, Letters, and Downloads.
Collect all Letters.
Have an Alchemist make you a new Spell.
Defeat Cantoran in battle. (Normal or Nightmare mode only)
Finish a character's entire quest line.
Defeat Xarion in battle. (Normal or Nightmare mode only)
Defeat Genza in battle. (Normal or Nightmare mode only)
Collect all Downloads.
Defeat The Maw in battle. (Normal or Nightmare mode only)
Defeat Aelana in battle. (Normal or Nightmare mode only)
Defeat the Golden Idol in battle. (Normal or Nightmare mode only)
Obtain an Orb without breaking its pedestal.
Defeat the Azure Queen in battle. (Normal or Nightmare mode only)
Finish a character's quest.
Find your first Familiar companion.
Defeat Varndagroth in battle. (Normal or Nightmare mode only)
Find a new Melee Orb.
Defeat the Feline Sentry in battle. (Normal or Nightmare mode only)