Oaken

So this merely states that you visited all 7 locations in the game, which can be done in the first two playthroughs, as the first run through puts you through 3, then the final wave. And then, you select the opposite 3 choices on your second run and it will pop right before the beginning of round 3 on your second run.

However, if you started playing the game before this title update, the achievement will not pop. Your only recourse that I found is to start a fresh save and play the first two rounds. Dumping your save file to an external drive is a good idea.