This is a fantastic game, I can see myself playing this for a long time. No real suggestions as you have it quite polished up. I played this tonight on my livestream and if you would like to see my impressions as I played you can see it here
Thank you Metalstorm for the review during your stream! :) To answer your question from the stream: the levels are randomly reordered before each start and generated from level layouts which are saved in bmp files.