Power-ups
Super Mario Bros. 3 features 13 unique power-ups, many of which can be used in creative ways to benefit the player. Aside from the iconic mushroom, which increases Mario's size and health, perhaps the most useful power-ups are those that feature the ability to fire projectiles. These include the fire flower and sledgehammer suit. The former can be commonly found throughout most levels, while the latter can generally only be won as a reward for defeating a pair of Hammer Bros. These power-ups are invaluable in boss battles.
Super Mario Bros. 3 features some more off-beat power-ups in the frog suit, which is found in aquatic levels and increases swimming speed, and the tanooki suit, which can be used to make Mario temporarily invincible. Items can be collected for later use on the map screen by visiting the mushroom-shaped buildings and by defeating enemies that walk along the paths connecting levels.
Warp Whistles
Super Mario Bros. 3 features eight kingdoms, each with approximately 10 levels, which makes progression to the final boss somewhat difficult. Massive portions of the game can simply be skipped by collecting hidden warp whistles, which can allow the player to entirely forgo kingdoms three through eight. In the third level of the game, hold down on the directional pad while standing on a white block. You will fall behind it. Progress to the end of the level to collect the game's first warp whistle. Another can be collecting in the miniboss' castle. Using the leaf power-up, fly above the ceiling at the rightmost screen of the level, at the door that leads to the boss battle. Access the warp whistles on the main screen and use the first one. Use the second one directly after and you will be able to warp to the final kingdom.
Lives
Collection of additional lives is a necessity for the completion of Super Mario Bros. 3. Players begin with four lives, but each level features hidden "1-Up" mushrooms, some of which are exploitable to dramatically increase a player's stock of lives. In the second level, find the leaf power-up and proceed to the area with the red Goomba that is followed by four smaller, yellow Goombas. Jump on the red one and hold the "A" button to fall slowly. Continue hitting the yellow Goombas that appear. You will begin receiving lives for each enemy defeated. This technique can be used in the pyramid-themed level of the second world, in the area where the pyramid itself appears. Jump on the Koopa repeatedly to continue gaining points and eventually lives. Look for any area that presents an opportunity to gain more lives with this method. Players can also start a two-player game and switch between Mario and Luigi to effectively double their starting life count.