Here is the full list of all 21 Ys SEVEN achievements.
Escort Tia back to Altago City completely unscathed, and without using any healing items.
Die by walking over thorns.
Die by drowning.
Unlock all bestiary entries for all non-boss, non-titano foes.
Find all the missing pikkards.
Learn every skill.
Raise all of any one character's skills to max level.
Buy every item from the Zanzibar Firm.
Synthesize each Spirit Elixir at least once.
Defeat all titanos.
Defeat Geis in one-on-one combat.
Survive against a beast intended specifically to kill you.
Conquer the Earth Dragon, Rada-Manj.
Conquer the Flame Dragon, Angue-Barl.
Conquer the Wind Dragon, Mu-Anti.
Conquer the Sea Dragon, O-Balon.
Conquer the Moon Dragon, Ze-Kalion.
Synthesize all Dragon Stone weapons.
Complete the game on any difficulty.
Complete the game on Nightmare difficulty.
Obtain all other achievements.