Full list of all 56 Tales of Zestiria achievements. It takes around 100-120 hours to unlock all of the achievements in the base game on Windows.
The base game contains 50 achievements, and there is 1 DLC pack containing 6 achievements.
Sometimes, after you've found a discovery point or when you're at a save point, you have the opportunity to press Enter/Back to initiate a conversation between your companions. This is proof that you've experienced many Things and had a lot of Opinions about them.