World 4-1 (New Super Mario Bros.)
World 4-1 is the first level of World 4 in New Super Mario Bros.. The level must be reached by using a secret exit in World 2-. The level has a Forest theme and has many Scuttlebugs, and a river of poison that is crossed by a Dorrie. This level also contains a Secret Exit.
Much of the level is flooded by poison. If Mario touches it, he will instantly lose a life. To start, Mario should keep walking until he finds some Scuttlebugs. He should jump on them to gain a jumping boost, which is used in collecting the first Star Coin. About halfway into the level, the player should see a Dorrie. Jump on it to ride it, while avoiding the Scuttlebugs. Mario does not need to ride the Dorrie as he can simply make long jumps and bounce off the Scuttlebugs and stand on blocks in between them. To get the second Star Coin, Mario again should get a jump boost from a Scuttlebug. After getting off Dorrie, Mario should jump onto the Donut Blocks to avoid falling into the water. The final Star Coin can be obtained by using a Koopa Troopa and throwing the shell at the coin. After this, Mario reaches the flagpole.
While Mario is riding Dorrie, the player should notice that on the way, there are two ? Blocks with three normal blocks in between. If Mario gets on top of them and jumps in the middle, a Beanstalk will come out of a Hidden Block. Mario must climb on it and enter the pipe to reach the Red Flagpole. The secret path opens up a Toad House and takes the player to 4-Tower.