FINAL FANTASY XV POCKET EDITION HD

There are four dungeons in the game, as follows:

Chapter 2: Keycatrich Trench
Chapter 3: Glacial Grotto
Chapter 4: Fociaugh Hollow
Chapter 5: Steyliff Grove

A lot of folks have complained that this achievement is glitched. To be honest, I started to believe it. But then I finally got it to unlock.

So, I'm not sure it's glitched so much as very particular. After completing the game in its entirety, I replayed Chapter 5 about five times and couldn't get the achievement to unlock no matter what I did. So I started from Chapter 2 and went through that dungeon, being careful to go back to the two locked doors after defeating the boss (which are now open). Still didn't get it. On to Chapter 3. After exploring every square inch and killing the Mindflayer boss in the Glacial Grotto dungeon it unlocked.

I think the issue might be that one cannot simply do the same dungeon over and over for the achievement to unlock, despite what the walkthrough says. I cleared my cache too, as I saw this might work. It did not. The best advice I can give is to be very thorough and to explore all paths. Take all paths in different directions too, as sometimes this triggers a new group of enemies. Destroy all destroyable objects and loot all goodies.

I could not find any video guides for this either. Sorry friends! I know this is frustrating, but trust that it will unlock.

*** I should note that I didn't have any trouble unlocking any other achievements ***