A later Adventure International title, Saigon: The Final Days, had as its very dark scenario the escape of a soldier from Vietnam at the end of the war. It was written by by Jyym Pearson and Robin Pearson.
A quirk in this game's input parser provided an unintentional surprise bit of morbid gameplay. At one point in the game, the player must figure out how to cross a predator-infested river. Entering the command "confess to war crimes" here would not be rejected as gibberish as one might expect, but would actually kill the player. This turned out to not be a planned feature; the parser was finding the command "swim" embedded in the phrase ("confess to war crimes"), and swimming across the river was invariably a fatal move.
The actual solution to the game was no less macabre, involving zipping oneself into a body bag to be carried out of the country by an evacuation helicopter.
Source: Wikipedia, "Adventure International", available under the CC-BY-SA License.