High Scores (Keen 6 Level)
This level allows Keen to play in front of the high scores. It is used so that whenever the high scores are displayed, a demo is running in the foreground to make the list somewhat more interesting to look at. This means the level data must be distributed with the game, and so warping to level 18 will allow the player to "play" this level.
Because the text displayed when entering the level says "Call Id!", many fans have wondered whether there is a way of accessing this level without cheating. The general consensus appears to be that there is not. Some fans even suggest this might have been related to the later Aardwolf easter-egg in Wolfenstein 3D, in some way.