This is a ROM hack of the Japanese NES game Zombie Hunter, modified by KingMike. It likely contains alterations to the original game, perhaps including updated graphics, gameplay changes, or translated text.  The 'En' likely stands for English, implying a translation from the original Japanese. Version 1.01 indicates a specific version update. The development history stems from the original Zombie Hunter but involves the efforts of the ROM hacker KingMike.  The hack may change the original's storyline, features, or overall experience. The modifications made are not officially part of the original game's release but represent fan-made improvements.

Zombie Hunter (Japan) [En by KingMike v1.01]

Zhen Ben Xi You Ji (Asia) (Unl)