Fun Fact: The “slime monster” from Dragon Warrior, or Dragon Quest as it is known in Japan, is practically a Japanese cultural icon. Dragon Quest had a huge impact on gaming in Japan.
Nowadays we would call Dragon Warrior a “JPRG,” or an RPG that is very heavy on character grinding to level up and inventory maintenance. For many North American NES gamers, Dragon Warrior would be their first exposure to this genre.
The goal in Dragon Warrior was to defeat the even Dragonlord. The game world was open for exploration. Tantegel Castle was the player's home base, filled with characters to meet and shops to provide gear. The further away from the castle players wandered, the more dangerous the creatures they would find in the wilderness.
Players explored the world from a top-down view, and when combat began the view would change to an adventure-game-type interface. Players could choose to Fight with their selected weapon, cast a Spell, use an Item, or Run. Combat was turn-based, so players could plan out their strategies. If the player died they were returned to Tantegel Castle with a penalty to their total amount of gold.
The success of Dragon Warrior was tied in no small part to a giveaway promotion with Nintendo Power magazine. It's estimated that 500,000 people subscribed to Nintendo Power and received a free copy of Dragon Warrior. The eventual success of this title is considered a turning point in gaming history, and could be considered the birth of JRPG popularity in North America. It also is considered to have been an important step in raising the visibility of the writers who crafted narrative in video games.