MERCS, referred as Senjou no Ookami II in Japan, is a run and gun arcade style military shooter developed by Capcom in 1990. It is the sequel to the 1985 game Commando. The third game in the series, Wolf of the Battlefield, was released in 2008.
The best known port for the game was the Sega Genesis version, which was reprogrammed by Sega themselves and released in 1991 in all regions. This version of the game included an Original Mode which was created specifically for the home market, with between-level weapon shops where players could purchase power-ups with items they collect in stages. There was also the standard Arcade Mode for the traditional experience.
The game has been ported to various platforms, the latest being on the PSP in 2006 in Capcom Classics Collection Reloaded. The Genesis version of the game arrived on the Wii Virtual Console in early 2009 under the name "Wolf of the Battlefield: Mercs." Capcom has loosely alluded to copyright issues over the Mercs name as the reason for the change.