The theme of this course is "Work It Out".
Reactive Factory is a factory complex built on a small island by Doctor Eggman. It is completely automated, and uses water as fuel to work. It is possible that the Reactive Factory was the place that Eggman created Metal Knuckles and Tails Doll. It is also where he altered his Egg Mobile, so he could take advantage on the World Grand Prix (the tournament depicted in Sonic R).