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 Mondoragon.
Defeat Black Rabite.
Defeat Anise on hard.
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.
Purchase nitromyte for the listed price.
Learn all abilities as any character.
Learn 20 abilities as any character.
Stop the end of the world.
Find Li'l Cactus in all possible areas.
Accumulate at least 500,000 lucre.
Max out magic pot level.
Become a master cleric.
Become a master fighter.
Become a master magician.
Complete Angela's story.
Complete Kevin's story.
Complete Charlotte's story.
Complete Chapter 6.
Defeat Dark Lich.
Open 200 treasure boxes.
Complete Chapter 5.
Accumulate at least 100,000 lucre.
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 companion's chain ability.
First time learning an ability.
First time learning a chain ability from an unexpected acquaintance.
First time planting a seed.