Worlds 5 and 6

Custom levels in World 5
Crystal Labyrinth
Buzzy Barrage
Focal Fortress [Note 1]
Icy Antics

Custom levels in World 6
Simple Skies v1
The Platform Defense/Dark Wooden Platform Defense by StrikeForcer
Tank Ship Trouble [Note 2]
Airship Atoll

Note 1: Focal Fortress was in Ultimate Custom Level Chaos, but it was altered to fit an end castle style level.
Note 2: Slowpoke Skies was originally the third level in World 6 but was replaced with Tank Ship Trouble due to crashing.