itch.io game lock

I have discovered that games you wouldn't think get stolen and posted to other sites do sometimes get stolen and posted to other sites.

This project uses emscripten and I have found and modified very simple javascript code so that the game will only run here (and where ever I decide to allow).  The code is as follows:

EM_JS(bool, verify_site, (), {
    if (document.location.host == 'html-classic.itch.zone' || document.location.host == 'localhost:6931'){
        return true;
    }       
    alert('This game can only be played at: https://nickthesic.itch.io');
    throw 'Please Visit https://nickthesic.itch.io';
    return false;
});

It checks that we are being loaded from itch.zone or localhost.  html-classic.itch.zone is what seems to work and I hope that itch.io doesn't change much to break this here.   While 'localhost:6931' is what the default is in emscripten and allows me to run the game locally for testing.

It is a pretty neat feature that I will most likely add to all my projects now and moving forward.

For your own projects be sure to:
1) Use a water mark.  Let people know who you are
2) Link back to your site in game.  Direct people back to your stuff
3) (Optionally) setup this verify.  As a gamer, I hate DRM.  But as small developer I very much see the appeal of locking my games to a specific site.  If you have a water mark or links it may not be as bad, but you should be in charge of where the game gets uploaded