Fun Fact: Rygar's ending was generally considered to be quite lame.
Rygar was an NES port of an arcade game developed by Tecmo. Where the arcade version was a side-scrolling action game, the NES version was much more open like an adventure game.
The player had to navigate the hero Rygar through five different worlds, fighting dinosaur-like enemies with the distinctive Diskarmor weapon, which was kind of like a yo-yo covered in razor-sharp blades. Most of the levels were side-scrolling platformers, but top-down levels served as bridges between major areas in the game. Rygar accrued experience points for defeating enemies, which the player could use to permanently power-up his abilities.
There was a recursive element to the game, as well. Rygar had to defeat the bosses guarding five Indora gods, and then confront King Ligar in a flying castle. Each Indora god would give Rygar an item, some of which could be used to access previously-inaccessible areas of the game like the grappling hook and crossbow.
Between its unique art aesthetic and distinctive soundtrack, Rygar made an impression on NES gamers as a solid adventure game early in the console's software lineup.