What are the advantages and disadvantages to using a game engine?

How do I know whether or not to use a game engine? I want to make a relatively complex 2D game for Android. What factors should I weigh to decide whether to find, install and learn a game engine or just do everything manually?

Answer

Advantages:

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  Most if not all of the coding is done for you, so all you have to worry about is content, level layout, etc.

  
  


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  Along those lines, memory management, asset loading, lighting (in complex engines), etc has all been designed and tested thoroughly (hopefully).

  
  


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  As mentioned below, if the engine is cross platform you will have to do little to no work to port your game.

  
  
  

Disadvantages:

• If you are modifying anything, you now need to become familiar with a new codebase.


• If there is a bug in the engine, unless it is open source you can't fix it.


• The engine was not designed specifically for your game, so it may be less efficient than code you write specifically for your game.


• Game engines generally are not free.


• If a game is small, the overhead of using an engine may not be worth the time invested to write code yourself.


• If your game engine also has any editors or tools, you will have to build and test those as well before turning them over to artists or relying on them yourself.

Don't let the fact that the list of disadvantages is longer: when the time spent coding and testing all the systems you need is too long for your production cycle, or if you have more skill with art than code, using a game engine is definitely a good idea.

A comparison of game engines is in the works in this question: Pro's and Con's of Various 3D Game Engines