so can U explain me what is outdated? I think this its symplistic enough...
I'm no expert in web design and in fact I have a very bad taste for such things, but the general idea is:
The background and the main content holders got a decent set of colours, using different variations of brown. Then there're like random bright coloured icons and buttons placed all over it, even a bright green and red animated button, giving it a nice feeling of a random forum from 2000.
Newer designs tend to avoid underlines pretty much anywhere (except maybe to indicate on which page are you on, but even that you'd normally indicate otherwise). Another thing that's very popular is the components being borderless, so they're visually separated with their difference of background colour.
Bigger buttons and texts for links/buttons are often used too.
Trivial things such as having the contents of the "Game" site could be also listed on a dropdown menu when hovering over the "Game" button, so you could actually see the content without having to load a new site.
The site is not responsive, for example on a smartphone it retains the whole view. Including the fancy buttons and the two-column setup.
When you're logged in, the button placemement on the user control looks extremely awkward.
Again, I'm not a designer so you really don't have to take my answer seriously. A real web designer could probably point out several more reasons to why the site design is to be considered outdated by 2015 standards.