Around 15 years ago, there was a Half-Life mod released called International Online Soccer, which turned Valve’s classic shooter into a football game. Now, just in time for the 2018 World Cup, it’s back.
Ten years since its last update, the project is now a standalone (and almost entirely re-written for Valve’s Source Engine) entity called IOSoccer, and is available for free on Steam. It’s a multiplayer game where everyone playing takes control of a single player, and games are played in third-person.
Being a free mod it of course has zero international licenses, though you can edit pretty much everything, from stadiums to balls to kits, to get them matching the real thing. And being built by fans atop Half-Life means it’s also not exactly an accurate football simulation, but the fact it uses keyboard + mouse makes for some interesting control solutions.