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