You can have a gaming niche Affiliate site where you can compare the new game to some of the more famous ones you've mentioned. That will bring new eyes to it. Then you can also recommend gaming equipment someone might need for playing this new game and link to Amazon. Set up Adsense as well. Also, you can make merch and promote it on the site or a dedicated Instagram page. I don't know - I suppose it depends on the direction you'd like to go in. You can also try to do something on Twitch or YouTube, for good measure. How far are you willing to go for a game that hasn't made it big yet?