CK Guy's 1st Levelpack
CK Guy's 1st Levelpack contains only one custom Keen 3 level, which is set as level 1.
There are points in some areas at the very bottom, which couldn't be seen during in-game. The level is considered as very tricky, right out of the gate. It involves much backtracking and obscure tricks.
Spoiler warning! This shows the whole level.