FUNDAMENTALS OF GAME DESIGN, SECOND EDITION
Hybrid Games
Some games cross genres, combining features not typically found together. This occasionally happens when two people on the design team want the game to belong to different genres, and they compromise by including challenges from both. Crossing genres is also sometimes an effort to appeal to a larger audience by including elements that audiences for both genres like. By far the most successful hybrid is the action-adventure, as seen in the more recent Legend of Zelda games.
(The earlier 2D Zelda games were almost entirely action games.) Action-adventures are still mostly action, but they include a story and puzzles that give them some of the qualities of adventure games. Although it can add flavor and interest to a game, crossing genres is a risky move. Rather than appealing to two groups, you might end up appealing to neither. Many players (and game reviewers) prefer particular genres and don't want to be confronted by challenges of a kind that they normally avoid. Retailers who plan to purchase a certain number of games from each genre for their stores might not know on which shelf to put the game, and so will shy away from it entirely.
However, you should not allow these genre descriptions to circumscribe your creativity—especially at the concept stage. If you have a wholly new, never-before-seen type of game in mind, design it as you envision it; don't try to shoehorn it into a genre to which it doesn't belong. A game needs to be true to itself, so a truly hybrid game may need to mix challenges that aren't typically presented together. But don't mix characteristics of different genres without good reason; a game should cross genres only if it genuinely needs to as part of the gameplay. A flight simulator with a logic puzzle inserted in the middle of the game just to make the game different from other flight simulators will only annoy flight sim fans.
