First of all, i'm not a big fan of these sort of layouts but the colour schema goes extremely well in my eyes for the most part. The patterns for background although easy to code are annoying and obtrusive in my opinion, you would simply have them as a background in your CSS class.
<style type="text/css">
<!--
.content {
background-image: url(images/pattern.gif);
}
-->
</style>
<div class="content">
<p>Content Over Background Easily</p>
</div>
This wouldn't work although if you swapped the pattern and the current background over with a few tweaks here and there I feel that would work extremely well.
The header seems rather childish and although the name 'Pixel' is in there you don't see Pixel2Life or PixelDepth using actual pixel buildings in the header so that sums up a few things.
It's slightly unique
It's a little bit childish
It's probably ripped from someone else otherwise good job on the pixel art.The adverts seems to be a problem but with a slight bit of tweaking upto 780-800px it would fit standard adverts and would still work well on standard resolutions, the code would come into play again, PM me if you want help expanding it.
Where is your footer area for about, sitemap, contact etc and also your copyright disclaimers, you will need one of these most certainly and it would be best to tie it into your current design.
Good luck and I give this layout a 7 as it could do with some tweaking.