Aside from an introductory tutorial, the demo includes two other missions that let you drop flour bombs and fly to (and land at) various airports. Most notable, perhaps, is the inclusion of the famed Princess Juliana International Airport, with its tiny landing strip and low approach over the beach. The areas available to explore are in the Caribbean, including the Netherlands Antilles and surrounding islands. The provided planes in the demo are the Air Creation Trike Ultralight, Beechcraft Baron 58, Bombardier CRJ700, and the deHaviland Beaver DHC2.
The 625MB download is a bear, and the installation process is considerable, but once it's on your machine you'll be up in the air in no time. Although the demo for the in-progress game includes minor graphical errors that can make aircraft and scenery look slightly askew, there's more than enough fun to have with the four provided planes.
The prerelease demo for Flight Simulator X offers you three of those missions, one of which is a tutorial that introduces the basics of flying. Microsoft Flight Simulator X makes a major break from tradition with the inclusion missions to complete all over the world.