Customization plays a big role with online and single player games. It’s not exclusive to FPS or racing, but can be in World of Warcraft or Role Playing Games. It offers the gamer a sense of investment in the character. You took the time to unlock or find a rare item and it feels rewarding to be able to equip the item. In Sim City you can build skyscrapers and power plants where and when ever you want. Creative people show new ways of morphing Minecraft which came out years ago. It sometimes can reflect on your personality.
For example of someones customization of a car