Flyingmouse's Level Pack
Flyingmouse's Level Pack is a Keen 3 levelpack that contains 21 levels.
The variety of levels is huge, ranging from keycard puzzles, to black and white levels, to levels that must be completed while the Ankh is used, to simple and short levels, to very long levels. The worldmap is designed in a way where Keen find and complete a few levels that have a heart that must be shot, and then go into a flying ship.
Spoiler warning! This shows the whole levels.