In the first Leisure Suit Larry game, if you type 'masturbate'....
It'll give out this message...
Clearly one of the playtesters had a dirty mind.
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Hidden in the files of Atomic Bomberman is an audio track with the voice actors (Billy West and Charles Adler) swearing:
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Hidden in the Atari 7800 port of Karateka is this bizarre message:
Quote:MOMMY AND ME ARE ONE.
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There are pieces of cheese hidden in every level of Perfect Dark. Their purpose is unknown.
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That's all the interesting things I could find, but I can post more if I find anything else.