Well, if you have a htaccess file with:
[quote:2mup5z7a] # BEGIN EXPIRES
<IfModule mod_expires.c>
ExpiresActive On
ExpiresDefault "access plus 10 days"
ExpiresByType text/css "access plus 1 week"
ExpiresByType text/plain "access plus 1 month"
ExpiresByType image/gif "access plus 1 month"
ExpiresByType image/png "access plus 1 month"
ExpiresByType image/jpeg "access plus 1 month"
ExpiresByType application/x-javascript "access plus 1 month"
ExpiresByType application/javascript "access plus 1 week"
ExpiresByType application/x-icon "access plus 1 year"
</IfModule>
# END EXPIRES
And your exported game is inside a folder that has that htaccess at the root (tons of sites use this), the JS files to run the game will be in a cache you have to either force to expire by doing a hard refresh, or mess with the index file to add a version string to the JS files.