What are the different parts of designing a video game?

Depends on the game, and aren't always in this order, or parts happen at the sam time, but in general:
- Come up with an idea for the game.

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  Write a story.

  
  
  
  
  • Maybe also come up with idea for puzzles
  
  
  
  


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  Create artwork for the game

  
  
  
  
  • The characters, the backgrounds, objects, menu items. Anything you see.
  
  
  • Storyboard work, to help other artists and programmers and designers get an idea of what the game is supposed to be.
  
  
  
  


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  Program the game.

  
  
  
  
  • You have your game engine, that controls how all the pieces of the game work together. It can control how the characters and objects move and interact with other characters and objects, and the world in general (do fall through the ground, don't allow walking through walls).
  
  
  • You also have artificial intelligence. How the computer players / enemies interacted with you / each other. Artificial intelligence can be as simple as "If the player is to the left of me, move left." and "enemies always point at the character" and can get more complicated. They are often based on a set of rules for each type of computer player / enemy.
    
    
    • If there is an online part to the game, make the network code that allows the game to talk to other copies of the game, or maybe to a central computer the game maker controls (like world of warcraft)
    
    
    
    
  
  
  • If it's a complicated game, you might write tools that help other people build the game.
  
  
  
  


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  Test the game. As with anything that is built, it needs to be tested to make sure what was made is what they intended to make. Fix as much as they can.

  
  


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  Market the game. Convince people that they should buy it when it's released.

  
  

I'm not a professional game developer, and I know there is much more.