Humanity

Besides the Prologue, all other Sequences feature optional trials that are denoted with an A or B next to the trial number. Completing any one of these will pop this achievement!

Here is a full video walkthrough with all solutions, all Goldys, and achievements! (Timestamps in YouTube Description)

Start the 1st chapter called Awakening, advance through the first few stages, until you get to the first optional trial, Three Towers. There are 3 Goldy's you can collect here. But all you should need to do for the achievement is complete the trial for the achievement.