New Super Mario Bros.: 1-Castle

Time for the first castle! There are lots of tightropes, which allows us to bounce high. The castle has lots of lava and there are stone platforms that appear from and disappear into the lava. There is a spiked ceiling that raises and lowers, so don't get caught between it and the floor. In one of the gaps, we can wall-jump up for the first Star Coin. After the spike ceiling are more stone platforms. The second Star Coin hovers over the lava. There is a small stone platform underneath it, but it can be completely submerged by the lava, so time your jumps carefully. We can reach the third Star Coin using the last tightrope. Bounce from its center to reach a green pipe overhead which leads to the third Star Coin. Exit using the same green pipe and go through the boss door. We run into the battle room to find Bowser. We can defeat Bowser using two methods: jumping over or running under him and hitting the switch, which destroys the bridge and opens the gate, or with fireballs. Either way, he falls in the lava, surfaces as Dry Bowser, and goes back into the lava. I used fireballs. Afterwards, we hit the switch, the bridge falls away, and the gate opens. We find Peach and Bowser Jr., who grabs her and runs off to World 2. We can now save.