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