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