- Concepts Introduced: Menacing Meanies, White Willies, Item Poles, long jumps, double jumps
- Key Feature: Introduction to jumping
- Description: The stage starts out with three rows of Item Poles which feature, in order, Rockets, Potions, and Mushrooms. Then the stage will alternate between a stretch of enemies and a jump whose length increases. After three jumps, the enemies will change from Menacing Meanies to White Willies, and you will be challenged to perform double jumps where you must land on a short ledge before immediately jumping over another gap. The final jump is a long jump which requires you to hold up on the direction pad to complete.
- Concepts Introduced: Fire Poles, Bonus Stars, Warp Balloons, Extend Heart
- Key Feature: Running between Fire Poles.
- Description: In this level you meet the red fire poles. As opposed to the green poles which you intentionally run into for items, you must avoid these poles at all cost. One touch will kill you. They are set up throughout this level like slalom gates. If you run between them, you will collect Bonus Stars. After just four stars, you will encounter the first Warp Balloon. Touch it to be carried away and dropped off in bonus World 1-B. Here you are challenged to collect as many stars as you can. There are two poles in here, the first of which has a potion, but the last one contains an Extend Heart. Collect it for an extra life before you leave. When you return to the world, continue to run through the fire gates to collect stars. Eventually, you will have to leap over pits. Learn the timing to continue collecting stars as you jump. You will find a second Warp Balloon which deposits you toward the end of 1-B, so that you can collect a few more stars and another Extend Heart.
- Key Feature: Moving laterally to avoid Fire Poles in chasms.
- Description: World 1-3 starts out like World 1-1, with three sets of poles containing Rockets, Potions, and Mushrooms. After that, the stage alternates between mixtures of Meanies and Willies, and long chasm jumps. In these chasms, there are various rows of Fire Poles. It is difficult to sail across a jump without being required to move right or left as you jump in order to avoid hitting the fire poles. Stay alert to the poles as you jump over the gaps.
- Concepts Introduced: Invincibility
- Key Feature: Forced running through enemies and fire poles.
- Description: This level starts out with four sets of two fire poles followed by a green item pole. The poles contain, in order, a Potion, a Rocket, a Mushroom, and the last pole contains the first Invincibility. If you collect it, you can run fearlessly through the enemies, but be prepared as it last for an incredibly short amount of time. As soon as it ends, resume shooting at or jumping over the enemies so as not to get hurt. After the fourth pole, you will find that you have no choice but to run across a field of enemies and fire poles at top speed. After one instance of this, you will find another four sets of fire poles and green item poles, this time with a Rocket, a Potion, Invicinbility, and a Mushroom. Then you will have to run at top speed through another field of enemies and leap over a long chasm.
World 1 Boss
The boss of world 1 is a simple serpent beast. All you must do is focus your shots at the beast's head. When you shoot enough shots, the beast will change from purple to yellow, indicating that he is close to dying. Shooting the body segments doesn't help kill the beast any quicker, but it can help you eliminate an obstacle that can get in your way and kill you when you try to shoot the beast in the head from behind. Be sure to get out of the beast's way when it comes as close to the front of the screen as it can.