Here is the full list of all 33 Sunrider 4: The Captain's Return achievements.
See the secret end.
Get 10 hearts with Ava then pick her at the end.
Get 10 hearts with Claude and pick her at the end.
Get 10 hearts with either Icari or Kryska and pick either at the end.
Get 10 hearts with Lynn and pick her at the end.
Get 10 hearts with Asaga then pick her at the end.
Get 10 hearts with Cosette and pick her at the end.
Complete chapter 10.
Get 10 hearts with Sola and pick her at the end.
Cast Divine Prayer 5 times in a single battle without saving and loading.
Simultaneously destroy 5 enemies with Asaga’s Awakening splash damage.
Chain 5 or more melee combos with Icari.
Simultaneously hit 5 or more enemies with Sola.
Complete chapter 9.
Complete chapter 8.
Complete chapter 7.
End the Crow Harbor battle before time runs out.
Restore Sola’s lost memories.
Complete chapter 6.
Destroy 5 or more enemies at once with the Flier Drones.
Fully upgrade the Paladin.
Complete chapter 5.
Save the space whales.
Fully upgrade the High Roller
Fully upgrade the Maray
Complete chapter 4.
Fully upgrade the Dominator.
Fully upgrade the Arch Angel.
Fully upgrade the Phoenix
Fully upgrade the Spell Caster.
Complete chapter 3.
Complete chapter 2.
Complete chapter 1.