There must be an ultimate ending to your game, there should be well thought out quests along the way, character advancement should be easy in the beginning and harder as the character progresses.
The key element about an RPG is character development. Make sure that your character gets better skills and items as the game progresses. This gives the player a feeling of accomplishment and entices them to keep playing
A RPG or involves having your main character interact with the world and other characters in unique ways. Having custom design for their creation or name also helps. When talking to other characters there are usually various responses which can change the outcome of your character or even the game.
