Set in Japan during the Sengoku jidai—the "Warring States" period from the mid-15th century to the beginning of the 17th century—the game has players adopt the role of a contemporary Japanese clan, attempt to conquer the nation and claim the position of shogun. The turn-based aspect of the game focuses on a map of Japan where military force, religion, diplomacy, espionage and economics all influence the player's actions, whilst battles are fought in a real-time mode. Sun Tzu's The Art of War is central to the game; its precepts are quoted often and its strategies recommended.
This topic isn't necessary. There's a sticky in the screenshots board with a list of all of the requests of this nature, and Shogun: Total War is in that thread.
Also, the demo does not support widescreen. I know because I spent about six months going through that list downloading every demo I could to get comparison screenshots, and when appropriate, a detailed report.