There is a game (PLE) metaverse (multiverse), which is at the stage of development, elaborated concept and documentation, investors are few.
As it usually happens - the game needs users at an early stage ...
What are the options for developing a marketing plan, please share your experiences ...?
Launch alpha version with bug bounty or beta testing contest for the community. In the meantime, do collaboration with gamefi guild based projects to expand community which is the best option, IMHO. Also try to do partnership with well known VCs or crypto community to boost the launch of the project.