This game's achievements are currently broken with an update. You can revert to the original release and unlock achievements.
Here's a guide to download and install previous versions of steam apps:
https://www.reddit.com/r/Steam/comments/611h5e/guide_how_to_...(all credit to GMMan_BZFlag for this guide)
This particular achievement is obtained just by loading the game the first time.
=== EDIT: Latest update apparently fixes achievements. Will verify then update this solution