Rygar is unlike any other game I really know of. Rygar is a dead warrior risen from the grave to save the land of Argool from the evil Ligar (or something like that). To get this accomplished, he has to collect the five treasures from the Indora Gods (or whatever).
Rygar starts out a side scroller. Rygar can go left and right, jump, and use his weapon, the Diskarmor. Later, he can collect a grappling hook to use as well (by pushing up+b, or down+b, if applicable) and other items allowing him to access different areas of the game. When Rygar enters a certain door, he'll find himself in an overhead view, a la Zelda. From this valley (Garloz), Rygar can access the "levels" which can be either side-scrolling or overhead. At the end of each "level", Rygar encounters a boss, which, if he defeats, will allow him to see an Indora God and get a new item.
While this may sound like pure late-80s fluff, the game utilizes a unique RPG system to it, in which Rygar can gain experience by killing enemies, and use items and even magic!
TONE-----In the upper left of the menu screen, you can view Rygar's current Tone value. He starts out with a tone value of 30, and by defeating enemies, his tone will go up. A higher tone means more offensive power to Rygar. Rygar's power goes up quickly, so tone is invaluably important. For example, an enemy that takes 150 hits at a Tone Value of 30, will only take about 35 hits with a Tone Value of 109.
LAST-----Near Tone on the menu screen, you will see Rygar's current Last Value. Rygar's default Last value is 10, and this increases by defeating enemies, just like Tone. When Rygar gets a Last value of 48, his life bar is increased by one, much like a Heart Container increases Link's health bar. Now, each time Rygar's Last doubles (at 96, 192...and so on), Rygar's life bar increases by one. In addition to this, a high Last value can also give Rygar better defense (very slightly).
MIND POINTS-----When defeating enemies, sometimes they will drop star icons. By collecting these icons, you give Rygar "Mind Points". You can see how many Mind Points Rygar currently has by looking at the white dashes below his "Last" value. The maximum number of Mind Points Rygar can possess at any given time is 7.
MAGIC-----On the right side of the menu screen, under the word Potential, is a list of Rygar's 3 magic spells. To use a spell, select the spell you want to cast, and press 'A'. Power Up costs 3 Mind Points, Attack & Assail costs 5, and Recover costs 7.
ITEMS-----At the bottom of the menu screen, you can see 7 slots where Rygar's 7 collectable items will eventually be placed. On the lower left are the two items Rygar can use while on the menu screen. To use one of these items, select the one you want to use, and press "B".