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Focused on imparting a skill, lesson, or piece of information to its player that would be helpful to them in other aspects of life, such as a faster typing ability or knowledge about a period in history.

Science-fiction. Commonly including things like aliens, advanced technology, and settings of outer space or distant planets. 

Focused on using its text, moreso than its visuals or audio, to tell the bulk of its story/plot. (Still can have great audio and visuals, though!)