Namco has had some success with their spot-the-difference Machigai Museum series in Japan. When it got localized as Quickspot for North America it barely made a blip on the radar. In 2008 Namco Bandai is trying a new strategy, pitting the star of Case Closed in a mistake spotting DS game. Since Conan is a young sleuth with sharp eyes he is a fitting protagonist, but I wouldn’t expect much more than identifying differences and following a new Detective Conan story in Detective Conan Kieta Hakase to Machigai Sagashi no Tou.
While I do enjoy playing Photo Hunt, I would much rather have a touch screen Detective Conan mystery novel.