The Compass puts a red arrow on the HUD that will always point to the level exit, even when it's off-screen. The compass is usually somewhat helpful as it allows you to plan your route through the level more efficiently, allowing you to run to the exit quickly to escape the Ghost or take a shortcut to avoid enemies. The Compass is also handy in dark levels in case you lose your light source, or if you are holding something and do not want to give it up for a flare. The Compass will not point to secret level exits such as those to the Black Market or the City of Gold.