Complex sentence: The game features the characters from the "Double Dragon" series, Billy and Jimmy Lee, two young martial arts experts; also included are the three humanoid toad protagonists from the "Battletoads" game.
Split into simpler sentences: The game features the characters from the "Double Dragon" series, Billy and Jimmy Lee, two young martial arts experts. Also included are the three humanoid toad protagonists from the "Battletoads" game.