This Achievement is for beating the "Desert Temple", "Fiery Forge" and "Highblock Halls" levels which are end game levels being rather difficult with bosses. If a visual assist is needed I've included a walkthrough below with easy to use time stamps.
1:13:26 Fiery Forge Level
1:24:40 Redstone Monstrosity Boss Batle
1:28:11 Desert Temple
1:36:05 Nameless One Boss Battle
1:42:54 Highblock Halls