Here is the full list of all 17 Tailbound achievements.
Defeat the Omega Wolf
Defeat Jonas
Defeat the Veldrake
Defeat Ataraxios and all of his forms
Defeat the hidden boss, Rykah
Discover Alex in Netcon
Discover Poco in Netcon
Unlock all normal enemy scenes
Unlock ALL scenes in the game
Finish the game
Destroy all 8 P-AD cells for the good ending
Finish the game with the best possible ending
Finish the game on NG+
Max out your character's stats and skills
Touch grass.
Listen to everything Ashe has to say
Unlock all other achievements.