You can get Empire: Total War for half price or the special forces edition for an extra few dollars.
It's a brilliant strategy game that puts you in control of Elite army units. There are several modes of play that allow you to follow a full blown campaign from when the first settlers first established colonies on the North American continent, battles across Europe and India. Sea Battles are also included. The single missions include several beseiged fortresses where you are instantly put in charge of an army of soldiers that include grenadiers, infantry, cavalry and cannon.
You do require a free steam account and client which can be downloaded and registered via the following link:
http://store.steampowered.com/
Video:
http://www.youtube.com/watch?v=1y5O3iphzp0
http://www.youtube.com/watch?v=84P8y1vdBDE