Secrets: How to master one of the all time classics.
Hit the flagpole at the end of the level while the last number in the Timer is a 1, 3 or 6 to earn the same number of fireworks. Each firework will reward you with 750 points.
After you lose your final life, wait until the game returns to the title screen. Then press and hold A and hit Start to return to the first Level of the World you lost your last life on.
In levels 3-1 and 6-1, jump on the turtles that are climbing down the final steps to make them shells. Jump on the shell to make it bounce off the wall and then jump again to make it keep bouncing back and forth between Mario and the wall. Continue jumping on the shell for almost unlimited lives.