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