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 Black Rabite.
Defeat Anise on hard.
Learn all abilities as any character.
Become a master cleric.
Become a master fighter.
Learn 20 abilities as any character.
Become a master swordsman.
Play with all six main characters.
Complete Duran's story.
Complete Kevin's story.
Complete Charlotte's story.
Defeat Mondoragon.
Purchase nitromyte for the listed price.
Stop the end of the world.
Max out magic pot level.
Accumulate at least 500,000 lucre.
Become a master thief.
Become a master magician.
Become a master guard.
Complete Angela'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 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 Dark Lich.