The Phantom Blob's 1st Levelpack
The Phantom Blob's 1st Levelpack contains 10 custom Keen 3 levels.
A duplicate of level 4 is in the download link, but it cannot be accessed in the map. Level 16 from the original game can be accessed in the map, although cheats are required to do so. Most of the levels in the levelpack contain lots of Foobs.
Spoiler warning! This shows the whole levels.