Here is the full list of all 35 The Eternal Castle REMASTERED achievements.
Finish the third run
end game within 300.00 moments
Unlock all achievements
end the intro within 19.87 moments
Kill the God with your fists
End the game at 100%
Finish without ever dying
Finish the second run
Find all GLIDER fragments
Reach the Castle with the ship
Find all available items
Outrun the sniper
Make the Kranker happy
Unplug your friend
Save the AI
Destroy the Guardian
Use Adam
Find the Sword
Crash the ship before reaching the Castle
Grab the Scientist’s GLIDER
Kill the Scientist and his Wife
Kill the Kranker
Grab the Sniper’s GLIDER
Find the shotgun
Find the Grenades
Find the machine gun
Teleport to ship
Grab the God’s GLIDER
Find the mace
Find the axe
Find the hammer
Find the double barrel shotgun
Grab the Cyclops’ GLIDER
Find the gun
Use Eve