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