As a user, I want to see the games that I have with my friends so that I can plan multiplayer games with them or see their stats and rating for a game that I have in my backlog or completed. This would trigger a conversation for sure with them.
The next step would be to have notifications around this feature, like: Friend567 completed X game that you have in your backlog. Or : Friend567 added a game that you have in your backlog.