Sigi - A Fart for Melusina

This is a story related achievement and cannot be missed. You should unlock this within the opening seconds (just after finding the first “I” out of the 4 “S-I-G-I” letters) of the game in the prologue during a short cutscene. During the scene, Sigi will gaze at a mermaid and talk about her large...um...lungs. He will then mention an increase in pressure and will fart unlocking your first achievement in the game!