Game development is a complex process by which a game is produced. For most people, the computer game experience starts at the store and ends on the couch. Few realize that creating a game can be as complex as making a Hollywood blockbuster. Months of planning and preparation, script writing, casting, character development, cutting-edge technology and massive computing power go into making games. A contemporary entertainment game can take from one to three years to develop, though there are exceptions. : More

Stages in game development

:: The idea
Every game begins with an idea. The idea includes the aim of the game, its educational goals and funny elements. : More

:: Scenario development
The scenario is a detailed description of the idea and the main scenes of the game.
Non-entertainment games are usually focused on serios issues. Scenario development requires creativity and good knowledge of the topic of the game (human rights, cultural diversity, youth project management, etc.). Playing games is an attractive way of learning, but it’s important to find the appropriate combination of funny elements and educational goals in order to ensure the effective learning. However, to maintain engagement of the player in the learning process, relevant content and design is also important.

:: Storyboard
Once the basic game concept is decided upon, writers and artists work together on a storyboard. : More

:: Creating the characters
As the storyboard is made, designers begin to create the characters. : More

:: Putting all in motion
At this stage, the character is basically a digital marionette. The game developpers bring this figure to life by instructing the computer to move the character. : More

:: Game environment
One of the most important aspects of modern game creation is the environment. : More

:: Code
The code is what makes all of the game elements work together, though unseen by the user. : More

:: Postproduction and Testing
Once the game is complete, it enters the postproduction phase. This phase includes extensive testing, review, marketing and finally, distribution. : More

Sources:

:: http://www.pbs.org/kcts/videogamerevolution/inside/how/06.html
:: Articles and resources about Game development
:: Articles on game development
:: A leading resource for game development
:: A game development resource