For example, who knew there was a Game & Watch version:
Nintendo would later bring out a Micro Vs. Series of their popular Game & Watch games called Boxing over to North America in 1984. When it came time to rerelease it in 1988, Nintendo opted to renaming it Punch-Out!! for the unit, due to the popularity of the NES game. Players play on a side view of the action, directing high or low punches at each other. It has nothing to do with the arcade game, or any other game of the series for that matter as it's only similarity is that they're both about boxing. Nintendo would put this game in their Game & Watch Gallery 4 for the GBA and keep it's former name for all releases.
Read more at Hardcore Gaming 101.