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.
End the War of Sisters before any blood is shed.
Beat the game on Nightmare mode.
Acquire every Orb Spell.
Acquire every Orb Passive.
Collect all Familiar companions.
Collect all Downloads.
Collect all Memories, Letters, and Downloads.
Finish all character quests.
Discover 100% of the map.
Find all Melee Orbs.
Defeat Cantoran 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.
Obtain an Orb without breaking its pedestal.
Collect all Letters.
Collect all Memories.
Prevent the Qaelans from being persecuted by the Empire.
Defeat Nightmare in battle. (Normal or Nightmare mode only)
Defeat the Sandman in battle. (Normal or Nightmare mode only)
Defeat the Ravenlord in battle. (Normal or Nightmare mode only)
Finish a character's entire quest line.
Defeat the ruler of Lachiem.
Defeat Emperor Nuvius in battle. (Normal or Nightmare mode only)
Defeat Xarion in battle. (Normal or Nightmare mode only)
Defeat Genza in battle. (Normal or Nightmare mode only)
Defeat The Maw in battle. (Normal or Nightmare mode only)
Defeat Aelana in battle. (Normal or Nightmare mode only)
Have an Alchemist make you a new Spell.
Defeat the Golden Idol in battle. (Normal or Nightmare mode only)
Have an Alchemist make you a new Passive ring.
Finish a character's quest.
Defeat the Azure Queen in battle. (Normal or Nightmare mode only)
Defeat Varndagroth in battle. (Normal or Nightmare mode only)
Find your first Familiar companion.
Find a new Melee Orb.
Defeat the Feline Sentry in battle. (Normal or Nightmare mode only)