Error.

[cgamewithnormalgames]

Edit: Is this repo still supported?

[Michael Scholtz]

games_played is an array, so technically it should be possible.

steamUser.gamesPlayed({
  games_played: [
    { game_id: '15444025664222527488', game_extra_info: 'Non-steam game' },
    { game_id: '440' } // TF2
  ]
});

[Nikolai Vavilov]

If the Steam client can do that, then you can use NetHook to see what it sends. Otherwise only Valve knows if it's possible or not.