Minecraft: Story Mode

Story related, cannot be missed.

This will unlock at the very end of the chapter once you find the temple and go inside. You will need to craft a bow and arrows in order to be able to get across the trap. Then make your way upstairs and you can use the amulet, and then light up all of the lights near the map. After this you will have to make a choice about which character you will go looking for first, and the episode will end with a cutscene. You will then be showed an "On the next" cutscene. Afterwards you will be shown your decisions through the episodes, and the achievement will unlock. 

If at any point you find yourself lost, or looking for a visual guide of the chapter feel free to use this video for help.