Ys IX: Monstrum Nox

  • Flash Guard is incredibly overpowered. Not only does it negate damage from any source, it buffs your damage. You can even re-guard during a longer attack like a flamethrower.
  • Side quests listed as "short" need to be done immediately or they'll fail. Those and "people entries" in the Journal are the only missable content in game.
  • Creating a save file when you hit a restore point (telegraphed boss fight) will save you from progressing too far and failing, but there's no easy way to tell you missed a character note.
  • You'll have to be thorough in checking the local map in the districts and revisiting your home base if you're trying for completionism
  • There's a side quest for collecting little blue things hidden around the city. You'll eventually unlock the ability to see them through walls so don't stress too much about finding them all early.