An entertainment device for receiving images from a video camera, the device comprising: a combiner combining images captured by the camera with a computer-generated image of an object resting on a virtual surface so as to generate a composite image; a detector detecting image movement in the captured images in one or more contact point regions corresponding to image positions at which the object contacts the virtual surface; and an initiator initiating movement of the object to a new position with respect to the virtual surface in response to detected motion in the contact point regions of the captured images, in which: the detector is detecting whether a first image area which corresponds to a captured image feature is greater than a predetermined proportion of a second image area which corresponds to a full field of view of the camera; in response to a detection that the first image area is greater than the predetermined proportion of the second image area, the initiator is initiating movement of the object to an avoidance position within the composite image, in which the avoidance position is a forward image position corresponding to a lower edge of the captured images, so that the computer generated object appears as if in front of any real objects within the field of view of the camera; the detector is storing a background image representing an image captured by the camera in a calibration operation, and to subtract image pixels of the background image from image pixels of a current captured image so as to generate a foreground image; and the image feature comprises the foreground image. a combiner combining images captured by the camera with a computer-generated image of an object resting on a virtual surface so as to generate a composite image; a detector detecting image movement in the captured images in one or more contact point regions corresponding to image positions at which the object contacts the virtual surface; and an initiator initiating movement of the object to a new position with respect to the virtual surface in response to detected motion in the contact point regions of the captured images, in which: the detector is detecting whether a first image area which corresponds to a captured image feature is greater than a predetermined proportion of a second image area which corresponds to a full field of view of the camera; in response to a detection that the first image area is greater than the predetermined proportion of the second image area, the initiator is initiating movement of the object to an avoidance position within the composite image, in which the avoidance position is a forward image position corresponding to a lower edge of the captured images, so that the computer generated object appears as if in front of any real objects within the field of view of the camera; the detector is storing a background image representing an image captured by the camera in a calibration operation, and to subtract image pixels of the background image from image pixels of a current captured image so as to generate a foreground image; and the image feature comprises the foreground image. the detector is detecting whether a first image area which corresponds to a captured image feature is greater than a predetermined proportion of a second image area which corresponds to a full field of view of the camera; in response to a detection that the first image area is greater than the predetermined proportion of the second image area, the initiator is initiating movement of the object to an avoidance position within the composite image, in which the avoidance position is a forward image position corresponding to a lower edge of the captured images, so that the computer generated object appears as if in front of any real objects within the field of view of the camera; the detector is storing a background image representing an image captured by the camera in a calibration operation, and to subtract image pixels of the background image from image pixels of a current captured image so as to generate a foreground image; and the image feature comprises the foreground image.