Go through the green pipe embedded in the hill shortly after the checkpoint flag. Inside the hill you'll find the World 1-1 Stamp at the top of the clear pipe.
There are some hidden hidden blocks that form a staircase leading to a hidden room. Once on top of the ledge, go through the clear pipe in the wall to find the World 1-2 Stamp.
You can find the World 1-3 Stamp between two cliffs in the mountain face. It can be gathered by wall-jumping, climbing with a cat suit, or dropping down from above.
Take the right path instead of the hidden waterfall to collect to collect the World 1-4 Stamp. You'll need to make slow, sharp turns in the narrow water.
At the end of the level, turn all the switches yellow to lower the final platform that you can use to collect the World 1-5 Stamp.
Break through the gray brick blocks beneath the paw gear by kicking nearby soccer bombs to reveal the World 1-Castle Stamp.
Continue to World 2 Stamps
