I've hopefully taken on board some of the comments made previously, particularly about not polluting the global namespace. I don't think it's particularly elegant code - far too many nested ifs - but it works.
Anyway, I'm really pleased that I've now managed to complete two programming projects. I'll probably carry on creating the odd game here or there when I have the time, but I promise not to keep polluting the TuxRadar feed with information about it!
I love getting feedback, so please do send it. If you like the puzzles and would like to know when I finish new ones, just so I can get more feedback(!) you can always follow my personal Twitter feed (only started using this recently!) @jonrob.