Capcom’s 3D sound adventure, Nazo Waku Mansion, has a release date in Japan; the game is planned for an August 4th release, at 4,800 yen. In addition to its emphasis on 3D sound, Nazo Waku Mansion also avoids use of buttons.
Camera control is handled via the 3DS gyro-sensor; you move the Nintendo 3DS around to change the camera angle. Rooms can be scanned using the touchscreen, and interestingly, you can “talk” to characters using the system’s built-in microphone.
You can watch a trailer for Nazo Waku Mansion in this older post.