Along with the mechanics of the game being old school, the graphics are that way as well. Underworld Gold uses a fixed 1024x768 resolution that you can stretch out to full screen or play in a window. All of the locations and enemies are in 2D, and the colors use a basic palette. The good news here is that while you won't ooh and ahh while viewing the scenery, the system requirements are minimal. You should be able to play Underworld Gold on just about any computer.
I played version 2.0.16 of Underworld Gold, and sadly it's still a little bit sloppy. Some parts of the game haven't been implemented yet (you're supposed to get attacked sometimes when you rest, but it doesn't happen), some parts of the game don't work (a strength-increasing beverage always claims you've already drunk it), and there are a host of silly typos (like "antichamber," "prisonner," and "pondered silk gown"). Fortunately, none of these problems prevent players from completing the game, and Charles Clerc has been very good about releasing updates, so hopefully he'll get everything straightened out soon.
Overall, I had mixed feelings about Underworld Gold. It reminded me of my youth playing RPGs (and breaking out the graph paper and colored pencils), but I'm not sure if I wouldn't have been better off playing one of those older games rather than this new one. That being said, Underworld Gold is only $15, it works just fine on Windows 7, and it gives you about 40 hours of content. It wasn't my favorite game of the year, but it seems like a fine risk if you're looking for something different to try.