Here is the full list of all 44 Trials of Mana achievements. It takes around 50-60 hours to unlock all of the achievements on Windows.
Stop the end of the world.
Learn all abilities as any character.
Become a master thief.
Become a master magician.
Become a master swordsman.
Complete Duran's story.
Complete Angela's story.
Complete Hawkeye's story.
Complete Chapter 6.
Defeat Mondoragon.
Complete Chapter 5.
Learn 20 abilities as any character.
Max out magic pot level.
Open 100 treasure boxes.
Complete Chapter 4.
First ride on Flammie.
Complete Chapter 3.
Complete Chapter 2.
First ride on Vuscav.
First class switch.
Complete Chapter 1.
First cannon ride.
Purchase nitromyte for the listed price.
Accumulate at least 500,000 lucre.
Accumulate at least 100,000 lucre.
First encounter with Li'l Cactus.
First time learning a companion's chain ability.
First time learning a chain ability from an unexpected acquaintance.
First time planting a seed.
First time learning an ability.
Obtain all achievements.
Play with all six main characters.
Complete Kevin's story.
Complete Charlotte's story.
Complete Riesz's story.
Open 200 treasure boxes.
Defeat Anise on hard.
Defeat Dark Lich.
Defeat Archdemon.
Defeat Black Rabite.
Become a master fighter.
Become a master cleric.
Become a master guard.
Find Li'l Cactus in all possible areas.