Single Envelope Syndrome occurs when a media that "pushes the envelope" in one way will flatly refuse to do so in almost any other way in an attempt to play it safe. A distant cousin of Rule Abiding Rebel; this is when a legitimate rebel in one or two areas will make sure to ovey all the "rules" in the others.

Examples:

.Immortal Defense is a deep, enlightening and somewhat disturbing game about immortality, life, love and madness. So it's understandable that all the characters with any kind of power are male (or possibly gender neutral, in the cases of Aa and Jamesh); the only female in the game is the helpless person you're protecting.

.The game 'I have no mouth and I must scream' is a borderline case. It definitely pushes the envelope; the storyline is engaging and uniquely dark, as are the puzzles. The fact that there is only one black character (who also happens to be the only female) is somewhat countered by the fact that she is the most important character, and the joint most sympathetic.