Had a quick look, confirmation worked fine (apart from email going to Spam folder), quite like the Bitcoin Shooter game.
You need to fix the HTML code on your referrals page though. With referral code taken out, your page shows it as:
<a href='https://funforcoin.com/register.htm?data=REFCODE><img src='ads.funforcoin.com/728x90.gif' target='_blank'></a>
To get it to work, I changed this to:
<a href="https://funforcoin.com/register.htm?data=REFCODE"><img src="http://www.ads.funforcoin.com/300X250.gif"/></a>
(My code may not be the best possible version of what you need btw, but it does work!)
I think this affects your referral code on all image sizes.
All the best with development of your site, it really looks quite promising.