Faxanadu (1989) — a contraction of "Famicom Xanadu," a spin-off of Falcom's Xanadu — is a side-scrolling action-RPG set inside a giant World Tree, where elves and dwarves are at war and a poison is spreading from the roots.

You buy gear and spells with gold, grow stronger, and save progress via long mantra passwords. But the thing people remember is the mood: melancholy music, eerie towns, and a lonely, end-of-the-world atmosphere unusual for the NES.

It's not as famous as Zelda II or Castlevania, but ask anyone who played it and they'll get a faraway look. A hidden gem with a soul.