Mega Man 4 is not as uncommon as some other NES games, but it might be tough to locate in its original packaging, especially in good condition. The popularity of the game, paired with its scarcity, has increased its value among collectors. One reason for the game's success is that it is one of the most critically regarded entries in the Mega Man series, with many fans hailing it as the franchise's pinnacle. In addition, Mega Man 4 added several new innovations to the series, including as the charge shot and the option to summon your robotic canine buddy, Rush, to assist you with various tasks.