And what are you linking against, then? I can make a tiny .jar file as long as I get to completely ignore the size of the JDK, much like you're ignoring the size of the libraries you're linking against.
The only dependencies this particular ex has is on user32.dll and kernel32.dll so it can call LoadLibrary and GetProcAddress, but if I wasn't interacting with those I could remove those dependencies (though then the exe wouldn't be able to do a whole lot of interesting things).
If you look at the file in a hex editor, it's mostly just empty space as it just has four 1k sections with a little bit of data at the start of each.