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