Your version of PHP is extremely outdated and susceptible to attacks.
Also, just navigating between ranking tabs banned my IP from your server. Seems like your settings are way way way too strict, and you're going to just end up banning all potential players before they even have a chance to register or download the client...
I'm not able to check if you're saving passwords in plain text or not, so players should be cautious when joining. Considering they're that outdated with PHP, I would assume they're also storing passwords in plain text.