Kingdom Hats

Kingdom Hats is a spin-off crossover game in development by Square Enix and Valve Corporation as a cross-promotion between Square's Kingdom Hearts series and Valve's Team Fortress 2 first person shooter.

Story
Following the completion of Sora and Riku's Mark of Mastery exam, Sora stumbles upon another dimension with new worlds including, but not limited to, a zombie-infested city and a vast laboratory run by a rogue AI, eventually coming across Teufort, a world where hats are currency and a true icon of social status. With time, Sora learned the tricks of the trade and worked his way up in social stature, and after finding the magician Merasmus, gains the right to return to Destiny Islands.

Development
Kingdom Hats was announced by Tetsuya Nomura at the APF video game developer conference held in San Antonio, along with a short two minute trailer featuring an FMV of Sora's hat-gathering journey.

Worlds and characters
The world of Teufort is split into different areas, each representing a map from Team Fortress 2.

NOTE
Thank Kingdom Hearts Wiki for the idea. Without them, Kingdom Hats wouldn't have existed.