Thanks for the positive feedback. I'm glad that you seem to like it and it certainly gives me reason to press on with it, or other games, in the future.
Regarding the use of the Mario graphics I suppose you're right so I've removed the download links from the blog.
The mario graphics were only used so I could get the thing up and running and looking somewhat presentable in a reasonable time. I was, after all, only developing this in my spare time to learn about basic games development and so didn't want to spend forever putting together graphics. I had no interest in ever distributing a finished game and only uploaded it here so that I could get some informed opinions on how it was going. Anyway, I've taken it down now.
Thanks again for the feedback!