I'm not sure how you feel about text-based interactive fiction games, but there is a great program that would let you build your world from scratch, and the program is fairly easy to use. You don't need to know any coding languages either. I believe you can add pictures and sounds as well. They have a great community that is very friendly and helpful. It's called ADRIFT.My current dilemma is that I am wanting to create at least one fantasy world from scratch, but can't find a sufficently good generator to accomplish the task.
This toolkit will allow you to create rooms, items, etc. It may not be the type of world you were wanting to create, but at least it's an option.
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