Hunt-the-pixel

Some [point and click]? [adventure game]?s include puzzles whose sole difficulty lies in finding a needed object on the screen. In cases where this object is shown quite small (i.e. only a few pixels) this pursuit is called hunt-the-pixel.

Often one does not have the faintest idea what gizmo one is looking for; only that the game won't progress without it.

A typical example from LucasArts' [Indiana Jones and the Last Crusade]? is where you drag your pointer over ten screenfull of bookstacks to find the manual that will be of use much later in the game.