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