genpei touma den
A 1986 arcade game (later ported to various platforms) by Namco. Based on the Genpei War, you play as Taira no Kagekiyo and fight Minamoto no Yoritomo & company. Fairly popular in Japan, of course. This game was included in Namco Museum Vol.4; for that compilation's English release, the game was listed as The Genji and the Heike Clans, although the game itself seems to be unaltered.
Related products include an interactive board game involving a Famicom cartridge for play (源平討魔伝 コンピュータボードゲーム; Genpei Touma Den: Computer Boardgame, and a sequel to the original arcade game (源平討魔伝 巻ノ弐; Genpei Touma Den: Kan no Ni) which was properly released in America (as Samurai-Ghost, with minor changes) for some reason.