I tried to download your demo, it says that "it's not a valid Win32 application".
I'll look into this. What's your OS?
I'm using Windows XP.
That could be it I'm afraid. Do you have Windows 7/8 anywhere? It's an OS thing
You really should be able to support the older operating systems with a project such as this.
Have you thought about learning to program in C++ so that you can make this without having to work around something like GameMaker?