Here is the full list of all 40 Lost Ruins achievements.
Collect every piece of equipment.
Defeat 50 enemies with a Sledgehammer.
Defeat 20 enemies with a Holy Sword.
Earn 999 gold.
Defeat 47 enemies with a Gladius.
Defeat 30 enemies with Runic spells.
Defeat 44 enemies with Corpse Absorption spells.
Defeat 50 enemies with ice spells.
Complete Assassin Mode.
Consume 100 Meat items.
Complete Witch Mode.
Arrive at the end.
Destroy 5 icons.
Open every treasure chest.
Defeat 5 Orcs.
Visit every area.
Block 50 Attacks.
Land 50 attacks on enemies by penetrating their shields.
Collect every artifact.
Defeat 30 Plant monsters.
Defeat 20 enemies by using traps.
Discover another ending.
Collect every record.
Defeat every boss.
Complete every quest.
Defeat Sadora the Ascetic.
Defeat 10 Banshees.
Defeat 50 enemies with Fire spells.
Defeat 60 bugs.
Hear all of the Goblin Merchant's tales.
Unlock every art piece.
Defeat 66 Demon or Undead enemies.
Arrive at the one true ending.
Inflict 50 critical hits with a Bow.
Inflict 30 critical hits with Throwing weapons.
Collect every Spell.
Deflect 20 enemy attacks with a Katana.
Collect every weapon.
Complete Hardcore Mode.
Complete Boss Mode.