About Condemned

Birds can be found by following either the buzzing of flies or the squawking/flapping of live ones. Usually few birds are found by the help of a cinematic showing them - during conversation or just the camera passing by an angle from which they're visible - or the game allowing you to use the smell-o-detector (or whatever) to locate them.

Metal plates are surrounded by black scribbles of eyes and the occasional bird, but mostly just eyes.

There's also one special item in each(?) level in the form of a TV with VCR nearby. These are usually in some side room or similar which easily go unnoticed and have no clear markers to guide you there (than perhaps the static sound coming from the TV).