1. A method comprising: receiving by a computing device an input to initiate a game application, wherein the computing device comprises a camera and a graphic display; causing the game application to initiate a game; and during gameplay of the game: operating the camera to capture image data of an environment; operating the graphical display of the computing device to display a graphical silhouette object having a shape, wherein the graphical display provides a field of view of the environment and displays the silhouette object such that it is overlaid on the field of view of the real-world environment; receiving input data indicating a desired alignment, in the field of view provided by the graphical display, of the silhouette object and a real-world object in the environment; responsive to the input data indicating the desired alignment: (a) analyzing the image data of the environment to detect the real-world object in a portion of image data corresponding to the input data, and (b) determining one or more similarity measures that indicate similarity between the real-world object and the graphical silhouette object, wherein at least one of the similarity measures indicates similarity between a shape of the real-world object and the shape of the silhouette object; and causing the graphical display to display a match indication based on the one or more similarity measures.