Rockstar Games suffered from arguably the most controversial Easter egg in history, even though it was an accident. Instead of removing the Hot Coffee mini-game from Grand Theft Auto: San Andreas entirely, Rockstar merely cut it off from the rest of the game – leaving the assets on the disc. It proved a simple matter for hackers to get their hands on the mini-game, and the more explicit sexual content caused Rockstar a lot of problems.
Despite showing nothing more than fully clothed bumping and grinding between consenting adults, the whole game had to be withdrawn and reclassified. The end result was millions of dollars of revenue lost and several class action lawsuits. Rockstar cheekily renamed the more moderate romance achievement in GTA IV after the incident; a polite cut-away to a building roof now throws up the message 'Achievement Unlocked: Warm Coffee'.

Another classic example is the game SimCopter, which was released in 1996. One of the programmers, Jacques Servin, added an

When I was in the video game business, I considered Easter Eggs to be highly unprofessional, but programmers kept sneaking them in.