Zelda II: The Adventure of Link  

     Zelda II: The Adventure of Link is a game that was made for the NES back in 1987. Although not the first two games in the chronological time line, this game and the one that came before; The Legend of Zelda were the first Zelda games to be released. This game references characters that would be introduced in a future title that would take place before that game. Looking at the game you could see that Nintendo was trying to figure out what type of game Zelda should be. There are elements of the game that have not been seen since, and some that are only now resurfacing. 

Sources:

I am mostly using the Fandom Site, for the lore of the games but I am familiar with every game in the series.

I am also using the art from the Manual as a reference.