An unusual place to find a flight simulator included, is Google Earth, but what a wonderful idea.
To use this flight simulator enter "Lilienthal" in the "Fly To" box, or type Ctrl-Alt-A in Windows/Linux, or Command-Option-A on a Mac.
Then, "Enter Flight Simulator" should appear in the tools menu in Google Earth for future use.
The keys are simply to use, pressing the PAGE UP key moves forward, space bar pauses, and CTRL and arrow keys allow you to turn the view. It's also possible to fly using a mouse or joystick.