Microsoft Flight is a simulation game which looks a lot like a cut-down version of the old Microsoft Flight Simulator, but aims to be easier to use, more accessible to everyone.
The new approach is obvious right from the start. You're not left browsing complex instrument panels, for instance, or wondering how to take off. Instead you're launched into a gentle opening mission, talked through how to manoeuvre around some balloons, and in the process learn how to turn the plane, increase or decrease the throttle, climb or fall, and so on. It's all very straightforward, and while the plane is still more naturally controlled with a joystick, you don't need one; we completed our opening mission first time with keyboard and mouse alone.
As time goes by you then get offered (or can select) other missions, which extend your flying skills in various ways. The ability to log in with Games for Windows LIVE allows cooperative gameplay with friends, and this all happens in a visually appealing world with realistic scenery, authentic weather patterns, terrain and flight physics.
The core program is free, but in part that's because it's relatively cut down in comparison with the old Flight Simulator; your plane is a fairly basic Icon A5, and you can only fly around the Big Island of Hawaii. Additional content is available if you sign in via Windows Live, though, and other commercial extras are available. You can already purchase a Hawaiian Adventure Pack to add more scenery, for instance, or upgrade your plane to a P-51 Warbird, or a Maule M-7-260C (and then fly extra passenger or cargo missions).
Perhaps the only real problem here is the download size. While the setup file is tiny (under 1MB), it will probably need to download something like 1.4GB of data to install the program, worth bearing in mind if your internet connection is slow.
If you like the idea of flight simulators, but have been put off in the past by their complexity, Microsoft Flight should appeal. It looks great, but is far easier to learn than Flight Simulator, and you'll feel comfortable in the cockpit right away.