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.
Accumulate at least 500,000 lucre.
Purchase nitromyte for the listed price.
Defeat Black Rabite.
Stop the end of the world.
Defeat Anise on hard.
Max out magic pot level.
Become a master cleric.
Become a master magician.
Become a master swordsman.
Complete Duran's story.
Complete Angela's story.
Complete Charlotte's story.
Complete Chapter 6.
Defeat Mondoragon.
Accumulate at least 100,000 lucre.
Complete Chapter 5.
Open 200 treasure boxes.
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 a companion's chain ability.
First time planting a seed.
First time learning an ability.
Obtain all achievements.
Play with all six main characters.
Complete Kevin's story.
Complete Hawkeye's story.
Complete Riesz's story.
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.
Find Li'l Cactus in all possible areas.