As a series of cutscenes, there are multiple outcomes for each decision you make for the game. You can still unlock and redo a chapter if you want to try something; like this

The Quarry is a game that contains several series of cutscenes where your chosen brand or action affects its outcome. The decision made by the player will determine the ending of the story where each mode contains "everyone lives", "everyone dies" and "gorefest".

To unlock the chapters, all you need to do is finish the entire story.

When you want to change the ending of the story, your option is to uncheck a chapter in this game and choose a different decision.