The Episode 6: A Portal to Mystery Add-on for Minecraft: Story Mode - A Telltale Games Series (Windows) has 6 achievements worth 125 gamerscore.
Complete Chapter 6 of Episode 6
Complete Chapter 5 of Episode 6
Complete Chapter 4 of Episode 6
Complete Chapter 3 of Episode 6
Complete Chapter 2 of Episode 6
Complete Chapter 1 of Episode 6