First Impressions: (10 out of 15)
Honestly, I first glanced at the site; it looked like Reddit--a site that I hate the design of. The "hot" questions with their answers located on the main page are cool and all, but very drab. I do have to say that the flat-colored theme is appealing, however. There is no "logo," at least, not in the traditional sense--it's just text which is also boring.
Site Structure: (10 out of 15)
Everything on the site is easy to navigate. I especially like that you have the option to read unanswered questions with the click of a menu button. The categories on the side fit nicely and also help with site structure. A big issue that I have with is there is no way to tell the total amount of questions and responses quickly like a regular forum. That said, this is far from traditional, but it would still be nice to have some type of member and post counts somewhere for us to see.
Design Quality: (7 out of 15)
I enjoy the flat colored theme and the way it's designed. Starting from the bottom down, the logo needs some work. The text is way too small, it's very plane, and it doesn't catch the viewers attention at all. The menu items are neat. I like the larger buttons with icons, not many forums use that. I also like how "hot" and "Ask a question" are colored differently. Selected menu items light up in a lighter blue color which is good too as it allows users to see which list they're on.
Honestly, I do not like the list-styled set up going on here. Simply, you just have questions and their answers in a list on the main page. That's boring as I said before. I would suggest maybe a different layout. You don't have to get rid of the theme, but how you layout the site might make a difference. Leaving the header (logo & menu area) where it is, you could arrange the main page and include three or four columns and then add a section or two to each. The sections could be the categories each containing the five most recent questions. And, find a way to decorate it up a little bit. Make it so that the first question in each category has some kind of image--that represents that category--behind it. Just a few ideas to help make it a little less dull.
Originality: (3 out of 15)
The site isn't very original. It's like Reddit as I said before. Simply, you have members ask a question and wait for answers. Reddit does the same thing with a lot more perks. I'm sure there are a bunch of other sites out there too. I can say, I've not seen a forum--other than Reddit--have this sort of layout. The flatness of the theme is unique, and the menu and navigation area is too, but the rest of it with the up down ratings, posting questions and answers, etc., is not original at all.
Overall Mark: (30 out of 60)
Overall, I think the site is an imitation of another. If you change up your layout a bit and even allow some different content, I'd be more inclined to enjoy it a bit more. For what it is, nice and appealing--for the most part--to the eye. Please remember this is just my personal opinion, based on years of experience. I'm not trying to hurt your feelings by being harsh.