Here is the full list of all 52 HunterX achievements.
Reach the next level.
Reach level 50.
Reach level 100.
Reach level 199.
Defeat the Priestess in battle.
Defeat the Blacksmith in battle.
Defeat the Witch in battle.
Defeat a specific boss.
Defeat a boss without taking any damage.
Defeat 5 types of bosses without taking any damage.
Defeat 10 types of bosses without taking any damage.
Defeat 18 types of bosses without taking any damage.
Acquire the Priestess' Curved Blade.
Acquire the Acid Dragon.
Acquire the Flame Halberd.
Acquire the Spider Saliva.
Acquire the Spirit Sword.
Acquire the Icy Beam.
Obtain Occult.
Obtain 5 types of Occult.
Obtain 15 types of Occult.
Obtain 22 types of Occult.
Successfully enhance a weapon.
Successfully enhance 1 type of weapon to max level.
Successfully enhance an Occult.
Successfully enhance 1 type of Occult to max level.
Remove all equipment and defeat a monster.
Penetrate an enemy with Shadow Dash.
Destroy an enemy's bullet.
Remove debuff.
Retrieve Karma.
Parry an enemy's physical attack.
Parry an enemy's bullet.
Resurrect after being killed by a monster.
Resurrect after getting caught in a trap.
Resurrect after being killed by a Debuff.
Explore every map.
Complete the monsters in your Archive.
Complete the items in your Archive.
Acquire all skills.
Destroy 666 Karma Crystals on the map.
Solve the special puzzle of Battle Ruins.
Solve the special puzzle of Castle: Lower Floor.
Solve the special puzzle of the Flame Dragon Temple.
Solve the special puzzle of Castle: Upper Floor.
Solve the special puzzle of the Born Tower.