Thanks CaptainD for your comment. You are right about it being slower and easier than the original and as I am new to making games I couldn't figure out how to flip the horizontal direction [the Scanner!]. But, I didn't want to give up because of that. The parallax varies from one to four layers of stars. You have a good eye for the the parallax view!
I have been working on my own version of Defender named "T A U S L E R" . I made all new sprites, backgrounds and sounds and added many more dynamic items of interest to add to the gameplay fun. The humans at the bottom are much more dynamic and involved in Tausler. I added many new ships and generally made it more of a fun experience than the old Defender manic experience [which I really used to love back in the day]. I haven't released Tausler yet because I really want it to be as awesome as I can make it for its debut! I will try to upload some images of Tausler soon and I would appreciate your comments.
Thanks again for your kind words.