Tony Castello is a member of the Castello Mafia family. When a business dispute with another powerful Mafia family turns violent, a war breaks out between the two families. Tony fights to protect his family throughout the mafia war. To win this difficult war, he will make new allies and work to increase his family's wealth and power.Along the way, Tony will meet new people and embark on new adventures. During the war, he forms a close friendship with James, and the war forces both Tony and James to leave their quiet lives behind and take on increasingly important roles. What begins as Tony's fight to protect his family soon develops in ways he could never have expected.

Castello is a third person shooter game centered around a crime story. While progressing through the main story missions, you are also free to explore the open-world city at your own pace. Gunfights, driving, and a variety of unique missions are among the game's core experiences.