Over two tons of Klay er, clay were used to animate the game.
The radio song "Sound Effects Record #33" contains backmasked singing in the shower. If you reverse it, the song being sung turns out to be "Khumbaya."
The radio song "Chiming In" is also backmasked. The eerie, dissonant sounds are those of a music box, and all the background noises captured while recording it—including someone breathing into a mic and the music box being wound.
Slow down the radio "song" "Scary Robot Man," and its true nature will be revealed: It's a sped-up, distorted ramble, done in a vaguely Indian/Hindi accent, about... being lost at a wedding, Slurpees, and McDonalds.
