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.
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 Passive.
Acquire every Orb Spell.
Collect all Familiar companions.
Find all Melee Orbs.
Defeat Ifrit in battle. (Normal or Nightmare mode only)
Defeat the Ravenlord in battle. (Normal or Nightmare mode only)
Collect all Downloads.
Collect all Memories, Letters, and Downloads.
Collect all Letters.
Collect all Memories.
Defeat the ruler of Lachiem.
Beat the game on Nightmare mode.
Defeat Emperor Nuvius in battle. (Normal or Nightmare mode only)
Finish all character quests.
Defeat Xarion in battle. (Normal or Nightmare mode only)
Defeat Cantoran in battle. (Normal or Nightmare mode only)
Defeat Genza in battle. (Normal or Nightmare mode only)
Finish a character's entire quest line.
Defeat Aelana in battle. (Normal or Nightmare mode only)
Defeat The Maw 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.
Have an Alchemist make you a new Spell.
Finish a character's quest.
Defeat the Azure Queen in battle. (Normal or Nightmare mode only)
Have an Alchemist make you a new Passive ring.
Defeat a boss without stopping time nor taking damage.
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)