How do you get users when there is relatively high barrier to entry when starting to use it?

My specific situation is a web game that requires you to play with multiple people (at least 3). I am getting visitors to my site, and they are even starting games, but they are not playing with real people. You can see my landing page here (https://phrenemies.com). Has anyone had a successful strategy when you need users to put in more effort than just clicking a download button or something?