Originally the game was going to be a mature-styled sequel to Kung Fu Chaos titled Kung Fu Story for the Xbox. However, development shifted over time into a new IP for the PlayStation 3.
Contributed by DrakeVagabond
When you play as Kai in chapter 3 to retrieve the Heavenly Sword for Nariko, you'll find Kratos's God Armor and Blades of Athena next to the Heavenly Sword from God of War.
Contributed by ProtoSnake