Ok, this is probably the last post on my first FPS game (though I'll let you know when I make something a little more exciting).
I used another nifty programme called Fraps to take a screen-capture of walking through the game last night and have squished it down to a suitable size for YouTube. As a result, the sharpness of the image is gone but based on the screenshots that I put up here the other day, you should still have some idea of what it's like.
(Here's an example of one of them - click on it for a full-sized version)
Here's the video.
I also realised last night that the background image I used in the second question was taken from the third level. Oh well.