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