Have you setup a cron job to nightly reset your arcade stats?
Cron jobs automatically execute various tasks on your preset schedules.
Take a look under your arcades 'admin/nightly.php', add that file as a 24 hour cron job under the server's cpanel.
Add something like (0 Hours, 0 Minutes, * Days):
php -q '/home/(your server directory)/public_html/admin/nightly.php' >/dev/null 2>&1
Your gameplay results, etc, will then reset when that is being called, at midnight server time, each day.
This is quiet mode (-q) with ignore output (>/dev/null 2>&1) so you don't get emailed each day about it.