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.
Become a master cleric.
Become a master magician.
Become a master fighter.
Play with all six main characters.
Complete Angela's story.
Complete Kevin's story.
Complete Charlotte's story.
Defeat Dark Lich.
Defeat Anise on hard.
Stop the end of the world.
Defeat Black Rabite.
Learn all abilities as any character.
Learn 20 abilities as any character.
Accumulate at least 500,000 lucre.
Become a master guard.
Become a master thief.
Become a master swordsman.
Complete Duran's story.
Complete Hawkeye's story.
Complete Riesz's story.
Complete Chapter 6.
Defeat Mondoragon.
Find Li'l Cactus in all possible areas.
Max out magic pot level.
Complete Chapter 5.
Accumulate at least 100,000 lucre.
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.
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.
Obtain all achievements.
Defeat Archdemon.