If you're into mystery games, you can definitely find friends in the Mystery Gamedev Discord server! That's actually one reason why I wanted to make a multiplayer game for the Mystery Game Jam. We need more friends in the world.
Also, if you're just curious how the game works, you can technically "play" it solo if you open up a few extra browser tabs. But I agree that a gameplay video would be nice to have on the page, too. Thank you for the feedback -- and glad it sounds interesting!