Red Ace Squadron is a computer vehicle simulation game

Vehicle simulation game

Vehicle simulation games are a genre of video games which attempt to provide the player with a realistic interpretation of operating various kinds of vehicles. This includes automobiles, aircraft, watercraft, spacecraft, military vehicles, and a variety of other vehicles...

 developed and published by Small Rockets

Small Rockets

Small Rockets is a small British computer game developer founded in 2000 that creates and sells PC computer games online.- History :Small Rockets was born from the ashes of Fiendish Games, a department of Criterion Games, that was started to test the waters for delivering games online rather than...

 in 2001. There is also an enhanced version named Red Ace Squadron Pro.
The game takes place World War I

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

. There are 10 missions by German planes (including Master mode), 10 missions by English planes (also including master mode), and a "secret mission".
A Pro version of Red Ace Squadron was released after a year of development.