I've beaten the boss a few times without it eating any corpses, achievement hasn't triggered? I thought maybe it was because I might have reloaded a save after he ate one, so I tried a run where I managed to beat him first try without him eating any, but still nothing?...

Title says it all, really. Just wondering, in case I want to shill for the game by posting the link to this demo Cheers

It says to "Open the Gates". There is no way to open the gates. Fun-o-meter trending negative at this point.

So, i just have to complete dungeons a couple of times or how am i supposed to get this achievement?

A few months ago i tried to get it but failed after a couple dozens of runs. Later i learned it was bugged. Is it still bugged?