When I clicked on the link using the latest version of Opera as my browser a window popped up telling me I'm not allowed to view the site unless I use IE.
Personally, I hate that. Lots of other people do as well. While I keep IE around to view sites that do not abide by HTML standards, there are people that don't even have a version of IE on their computers at all. This limits potential viewers from your website. I would say unneccessarily so, in that it is incredibly easy to make a website that is viewable in all browsers.
If you want to use web code that is not supported by anything except IE, it is possible to have the site, in regular, normal, HTML, detect the web browser and offer alternate code that is supported by every browser out there. You can probably find examples of the code over at http://webmonkey.com
and make your site accessible to a much wider audience.
Upon viewing the site, I noticed that the actual page looks pretty simple, the only possible non-web standard things seemed to be the things like the scrolling stars in the background, and the inner site that expands across the entire screen so that the viewer cannot even reach their task bar without closing the window. I imagine the stars thing is Java, which even people using the latest version of IE may not have installed, and the main page that covers the entire computer screen may drive off a lot of people.