This stage is Bowser’s Bullet Bill Brigade (2-Castle). This complete walkthrough will provide you with a 100% video playthrough and a screenshot of where you can find all the green stars. We will also note a secret 1 UP.
Game Play Walkthrough Video
Green Star 1
The first Green Star sits right behind three fire-spewing Piranha Plants. You won’t miss it.
Green Star 2
The second green star can be found inside a wooden crate on the second tank that you encounter.
Green Star 3
At the green pipe near the end of the stage. Don’t enter it yet. Use the cannon blast to break the Bowser face wall and get the final green star.
The stamp is shown on the tank after the second star. You simply have to jump fast to grab it before the screen scrolls.
Boss Fighting Tip
This boss is pretty easy. The only thing that you should watch out for is to stomp it with the right timing.