Complex sentence: On November 10,1981, Day opened an arcade in Ottumwa, Iowa called Twin Galaxies, though it was a modest arcade of merely 22 arcade games, it soon became known as the International Scorekeeper for the burgeoning video game industry.
Split into simpler sentences: On November 10,1981, Day opened an arcade in Ottumwa, Iowa called Twin Galaxies. Though it was a modest arcade of merely 22 arcade games, it soon became known as the International Scorekeeper for the burgeoning video game industry.