World 4-3 is a level found in the game New Super Mario Bros.
It's another automatic scrolling underwater level. What's new is the Mega Unagi that swims across the top of the screen only seconds after the level begins. Be sure to remain as low as possible. After that, Mario must swim as far as possible to the right so that he has time to collect the first Star Coin before the screen scrolls past.
Attempt the Red Coin Ring and watch out for small eels that try to bit toward both their left and right sides. For the second Star Coin, come right down directly on top of it to avoid the Unagi.
Before long Mario will come to a ? button on the ceiling. Hit the button quickly before the Unagi appears and they swim down to the bottom. If the timing is right, Mario should be able to reach the last pipe (green) before the bubbles come back on. Down this pipe is a secret room with the third Star Coin. Swim across the top to reach it.
Back in the water again it's only a short distance further before Mario reaches the final green pipe that takes him to the stage's flag.
- Star Coin 1: After the first Mega Unagi passes, the player should swim to the right and drop down and left to go under a rock formation where they can get the coin. If the player is not fast enough, Mario will be crushed between the scrolling screen and rock.
- Star Coin 2: The second Star Coin is located at the bottom of the level between two rock formations, where it is guarded by two Unagi.
- Star Coin 3: After hitting the ? Switch, the player should enter the lower right green pipe to be transported to an area with two Unagi and a red pipe spewing bubbles. The player should immediately swim over the left of the cave, go down past the Unagi and use the bubbles to collect the final Star Coin.