Level 6 is a secret level in Keen Dreams that cannot be reached from the map. It contains items that give Keen points, and has often assumed to be some kind of left over testing level. When using the warp cheat, it can be accesssed as levels 6, 8, 11 and 13.
It is unknown whether or not these incomplete levels were intentional, development of Keen Dreams was rushed, or because of some other problem. There are four empty levels which means there are 12 official levels in this game instead of 16.