There could be the player themselves as the main character, as they are the ones doing the creating.
It's hard to say for sure without more specific information about the game. But generally, the main character is likely the creator, which is the player. However, if the game has a backstory, there could be characters like the original creator of the game world, or some mythical beings that are related to the act of creation within the game's lore. For instance, in a game where the creation is based on magic, there could be a wizard - like character who taught the first players how to use magic for creation.
Perhaps there are in - game guides or mentors who help the player in their creation journey. They could be non - playable characters that offer advice on design, resources, or techniques. Also, there might be other players who play a role, like in a multiplayer version where they can collaborate or compete in the creation process. For example, if it's a building - focused game, some players might be known for their amazing architectural designs and they could be considered important characters in the overall story of creation within the game.