In the mission: "Come out Fighting", if the player jumps on the wire barricade connected to the second house then walks to the wall, they will be able to pass through the wall and see a secret room where they'll be able to see a UFO.
Contributed by Boyobmas
The game has a hidden, blackened room filled with candles and the ghost of a young boy in a baby's crib. The boy doesn't seem to acknowledge that the player is there, and blankly stares into space the whole time.