If you have Visual Studio 2003 installed on your computer, start ildasm.exe utility can be found at
C:\Program Files\Microsoft Visual Studio .NET 2003\SDK\v1.1\Bin
It is the .Net framework disassembler utility, open my galaxies.exe (File > Open), and it disassembles my application. You can see that, this is a standard managed application, all of the classes can be seen here, and all the code what this application do.
The app.config file is an option, it is not required to run an application. The same is true for the bin directory.