There are several red chairs dropped around the game. It has been assumed that they are a reference to Twin Peaks' second episode where Agent Cooper is dreaming of Laura Palmer the victim of the murder he is investigating.
The first two pages of the manuscript found in this level, the voice reading them out is Max Payne's voice.
Two crossed golden Beretta 9mm handguns are on display in Alan's apartment office. This could possibly be a reference to the Max Payne series, as the Beretta is Max's handgun of choice in Max Payne and Max Payne 2: The Fall of Max Payne.
The bathroom medicine-cabinet might also be a reference to the Max Payne games, as it contains only one single bottle of pills(the healing item in the series).
After you have seen Doctor Nelson, head towards Sarah Breaker's office, and on the wall are a list of missing people, who are actually video game developers.
When you wake up in the Cauldron Lake Lodge, in the room opposite (Emerson's room), on a table is an Xbox 360, with the game Night Springs, which is not only the show you watch on TV's around the game, but Alan wrote an episode for it.
Emerson, a crazy video game developer, makes a reference of Max Payne and the "Bullet Time" ability.
Shortly after you pass the Windmill on the way to the farm, just before the Stage, if you go left past the windmill to where the hidden chest is located, further back, behind the small barn, are 3 Crosses representing graves. Upon approaching these graves, the dark presence will take them over, and 3 Skeletons will rise out of the ground, and be flung at you, then reassemble and repeat, until you destroy them.
After entering Bright Falls Light & Power, Cynthia Weaver will lead you into a small room containing a bed and table. A book titled "How to catch a Dopefish" can be seen on the table with a picture of Dopefish against a blue background on the front cover.