Nicely done! AI users have been asking if they could do this kind of thing for quite a while. So I would not be surprised if we see Mario-type games and others down the road that include the side-scrolling or perhaps vertical scrolling.
I have not been able to get it to work on my Windows 7 machine yet. The app prompts for a tcpip address and port for the computer. I think I know how to get the tcpip address but the port? and there is no documentation for the app that I know of.
App Inventor is primarily an educational tool to teach programming that uses a simple scheme of blocks that snap together to form Android apps that can access the device sensors and do other things. More here: http://appinventor.mit.edu/explore/