Complex sentence: Glass Joe has become a well-known video game character since his debut in the series and is considered an icon of Nintendo and one of the most well-known characters in the "Punch-Out!!" series.
Split into simpler sentences: Glass Joe has become a well-known video game character since his debut in the series. He is considered an icon of Nintendo and one of the most well-known characters in the "Punch-Out!!" series.