This is part 6 of my 100% Super Mario 3D World Walkthrough.
This part includes World 3-Toad "Captain Toad Makes a Splash", World 3-4 "Pretty Plaza Panic", World 3-A "Magikoopa Blockade" and World 3-5 "Pipeline Lagoon".
Below are the times when I get the stamp and green stars in each level.
00:15 - World 3-Toad - Captain Toad Makes a Splash
00:36 - Green Star #1
01:00 - Green Star #2
01:25 - Green Star #3
01:38 - Green Star #4
01:55 - Green Star #5
02:36 - World 3-4 - Pretty Plaza Panic
02:42 - Green Star #1
03:18 - Green Star #2
03:38 - Pretty Plaza Panic Stamp Location
03:53 - Green Star #3
08:31 - World 3-3 - Shifty Boo Mansion
09:03 - Green Star #1
09:23 - Shifty Boo Mansion Stamp Location
09:57 - Green Star #2
11:50 - Green Star #3
05:28 - World 3-A - Magikoopa Blockade
06:19 - World 3-5 - Pipeline Lagoon
08:20 - Green Star #1
09:21 - Pipeline Lagoon Stamp Location
09:56 - Green Star #2
10:58 - Green Star #3