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