Dealing with Empty ball pit problem - Marketing question

I forget where I heard this expression but the idea is you want to build an amusement park but all you have is an inflatable pool right now with 3 balls in it. You need financing to build that amusement park but also you need people in your amusement park to get investors interested.

Obviously this isn't about a ball pit or an amusement park, it's about building a game community and that community would be players. I know dev vlog and stuff like that bring a different type of audience that is usually other game devs instead of players.

So I'm curious what type of content might attract players instead of game devs?

We are really close to having a demo of our game but I like to hype it up a bit so I'm looking for suggestions.