Woah, I completely never noticed the very top navigation. It's very odd because everything in the top navigation corresponds with a link in the secondary navigation below the Phoenix logo (why do we have duplicated links for Home, News, Games, Community, and Jobs?). I see how it sticks to the top of the browser, so you still have navigation when you scroll, but honestly, it does such a great job of being unobtrusive that its use is sort of lost. And the only page where you do a lot of scrolling (News), the bar stays at the top of the page, not at the top of the screen.
Like Aaron said, the background is really dark and scary compared to the rest of the site. Why don't you guys use the semi-transparent overlay like on the About page, for instance?
Also, I get that it's a different website, but it does seem weird that it doesn't share the same navigation (the home page on the store goes to the store home, not the POStudios home). A consistent site feel will probably make it feel a bit more legit. It may just be me but it kinda looks like the kind of website I would second-guess putting my credit card into, especially with all the minor yet distinctly present differences between the main site and the store (The background image, for instance, looks zoomed in a bit, like Erica and John are leering at me to buy something already).
For another cleanliness issue, I think having both PC and Mac on the main screen is making it rather cluttered. I mean, 4 out of the 6 items have the same image, and that sort of seems some combination of confusing and unprofessional. It makes more sense to me for someone to choose "Cognition Season Pass" and then, from there, choose PC or Mac. That way, with only two images there, it's more clear what the difference is (especially with the price difference right there).
The add to cart functionality works really nicely with a respectable amount of clicks-per-action, but there seems to be a problem with the CSS regarding adding one or more items, because it alternates between white on black and white on a blindingly light grey. At least it does on Firefox. (The same thing happens on the checkout screen)
And despite the cart working great, it might be nice to have some sort of "Buy now" option. Maybe a brighter button next to the Add to Cart button. Just think it'd be nice for people who want to go straight to buying the season pass for Mac and want none of your shopping cart tomfoolery. The problem is that that would require letting them choose between using the site and using Paypal and 3 buttons would probably just clutter it up. This is such a minor issue, so it's probably not worth worrying about, but it did strike me as I went to the site, so I thought I'd point it out.
At this point, the featured items is entirely redundant and is just a worse way of navigating the store. I can probably see everything you'd want to feature more quickly by just looking at the page than I can scroll through that box on the left. Even with that, it's very tiny, so if you do reach a point where your library is so extensive you need to feature things, it doesn't catch the eye much. And what does the Our Products link do? As far as I can tell, it just links to the store, and it's not like you have other people's products for sale...I'm a bit confused. And as you can tell, I'm big on things not being cluttered.

The rest of the site is very centered and I'm not sure there's a purpose to having those boxes on the side. Especially if getting rid of them would make the store items more easily visible.
In sum, more consistent CSS with the rest of the site, more obvious store link, combining PC and Mac versions on the front page, and the removal or repurposing of those boxes on the left. I know I give a lot of critical feedback, but most of it is just optimization and nitpicking. I'm really just trying to give you guys the most detailed feedback I can.

Also, yes, please add TSL. If we could get that download working intuitively, it'd be SO much more approachable to newcomers, which would create a better POStudios fanbase, who would buy more things.
