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 Anise on hard.
Learn all abilities as any character.
Become a master swordsman.
Become a master guard.
Become a master fighter.
Play with all six main characters.
Complete Duran's story.
Complete Kevin's story.
Complete Riesz's story.
Defeat Dark Lich.
Learn 20 abilities as any character.
Defeat Black Rabite.
Stop the end of the world.
Become a master cleric.
Become a master magician.
Become a master thief.
Find Li'l Cactus in all possible areas.
Complete Angela's story.
Complete Charlotte's story.
Complete Hawkeye's story.
Complete Chapter 6.
Defeat Archdemon.
Open 200 treasure boxes.
Complete Chapter 5.
Complete Chapter 4.
First ride on Flammie.
Complete Chapter 3.
Accumulate at least 100,000 lucre.
Accumulate at least 500,000 lucre.
Open 100 treasure boxes.
Complete Chapter 2.
First ride on Vuscav.
Max out magic pot level.
First class switch.
Complete Chapter 1.
First cannon ride.
Purchase nitromyte for the listed price.
First encounter with Li'l Cactus.
First time learning a chain ability from an unexpected acquaintance.
First time learning a companion's chain ability.
First time learning an ability.
First time planting a seed.