The itch.io forums: https://itch.io/community

Newgrounds: https://www.newgrounds.com/bbs

Gamedev.net: https://www.gamedev.net/forums/

I've heard mixed reviews of the game development Stack Exchange: https://gamedev.stackexchange.com/

But there's also separate SE sites or Stack Overflow tags for the major components of game development like 3D art (Blender) and toolkits (godot, unity, etc).

The YC for gamedev is Kickstarter or shopping a game around to publishers.