Here is the full list of all 26 Obludia achievements.
Complete World 2 – Ancient Tower
Slay 20 chickens.
Slay 100 monsters with blade.
Throw 50 dynamites.
Complete World 1 – Dungeon of Doom
Eat 20 Hamburger.
Fire 100 Shotgun Shells
Buy your first dog.
Slay your first enemy.
Find 20 chest.
Save 10 princess.
Slay 20 Devils.
Complete the game.
Complete World 3 – Frozen Island
Complete World 4 – Hell Gate
Complete World 5 – Space Ship
Die 50 times
Find the legendary golden monkey statue
Destroy 50 Alien eggs
Cast 50x Glacial Spike spell
Cast 50x Ring of Fire spell
Cast 50x Lightning Strike spell
Slay 30 Ghosts.
Use 10x Holy Cross.
Find 1000 Coins.
Complete the game on HARD mode.