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