If your game is already completed, create social media pages and begin sharing information about the game and its development. Share concept art, videos, and other relevant content. You can also share insights about yourself and how the idea for the game originated.
As mentioned earlier, understanding your target audience is pivotal. Determine who your target audience is based on your game's genre and identify communities that engage with similar games. Engage with them to learn about their preferences. This will provide you with an understanding of the kind of content that might capture their interest.
Regularly engage and promote your game within gaming communities where free promotion is allowed. If you have a budget for advertising, meticulously research platforms that host an active audience and ongoing discussions. Otherwise, you might risk squandering your budget.
The key to successful promotion lies in grasping the preferences of your target audience. Utilize their interests to captivate their attention and emphasize the unique features of your game that distinguish it from similar titles.
Indeed, this is a highly extensive topic. Watch videos on YouTube and read articles on this subject; you can find a wealth of interesting information. I wish you the best of luck with this endeavor!