"Battlestations: Pacific expands on Battlestations: Midway in several ways, adding new combat features such as island invasions, which have effects on the battle at hand. New weapons, planes, and ships were added, such as HVAR rockets and experimental jet fighters, including the Kikka and Shinden, along with kamikaze aircraft, such as the Ohka and Kaiten; there are also some more conventional aircraft and ship additions. Battlestations: Pacific shifts events beyond Midway for the American forces as they continue the war onwards to Okinawa, but the most drastic addition is that of the Japanese campaign, which tells a "what if" story in which Japan is victorious at Midway and continues their war effort beyond that point to invade Hawaii."
Source: Wikipedia, "Battlestations_Pacific," available under the CC-BY-SA License.