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