Crystalis — The NES's Other Great Adventure
SNK's post-apocalyptic action-RPG with real-time sword magic.
Released in 1990, late in the console's life, Crystalis by SNK is often called the NES's best Zelda-style adventure that isn't actually Zelda. You wake from cryogenic sleep into a post-apocalyptic world a century after a global catastrophe, and set out with sword and sorcery to stop it from happening again.
The combat is real-time and fluid, the four elemental swords (Wind, Fire, Water, Thunder) each charge up into screen-clearing magic, and the open world rewards exploration. It feels years ahead of its release.
Overshadowed at launch by the SNES arriving, it's since become a cult favorite. If you missed it, it's the great lost NES adventure.