A guide to completing World 1-1 in Super Mario Bros 1 for the Nintendo Entertainment System.
World 1-1 Part 1
Go to the right (you can hold B to run) and press A to jump to hit the glowing ?-mark block. You'll get a coin and 200 points. Then jump onto the Goomba (red walking mushroom creature) to get 100 points. (Points are only for high score purposes.)
The bottom-left ?-mark block between the bricks contains a Magic Mushroom, which will super-size Mario, turning him into Super Mario. If Super Mario gets hit by an enemy, he turns back into regular-sized Mario. If regular-sized Mario gets hit, you lose a life and start at the beginning of the World.
Also, Super Mario will break bricks if he jumps and hits them. Each broken brick is worth 50 points.
Go to the right and jump on top of the green pipe. Some pipes lead to secret areas if you press down while standing on them, but this one doesn't. Keep going to the right and jumping over green pipes until you reach two Goombas walking between pipes. Stomp them, then jump onto the pipe to the right of where they were. If you want to skip most of World 1-1 and get a lot of coins, press down and you will enter the pipe. Jump to collect all the coins, then walk into the pipe on the right, and skip to World 1-1 Part 2 below.
World 1-1 Optional Section
If you didn't go down the pipe into the secret area, go to the right from the pipe, and stand in front of the left side of the hill. Jump and you will reveal a hidden block. A 1UP mushroom will pop out. Collect the mushroom to get an extra life.
Go to the right and jump over the gap, then hit the ?-mark block to make a Fire Flower appear. (Or, if an enemy hit you and turned you back into regular-sized Mario, a Magic Mushroom will appear instead.) If you got a Fire Flower, you will turn into Fire Mario, and your clothing will change color, and whenever you press B, you will throw a fireball. You can hit monsters with these fireballs to get rid of them from a distance, but there will be some enemies in later worlds that are immune to the fireballs. If an enemy hits you when you're Fire Mario, you will lose your fire power and turn back into regular-sized Mario.
Feel free to break some bricks here to get some more points. Then go to the right and jump over the gap. The lower brick on this side secretly contains coins. Keep hitting that brick until coins stop popping out. Then jump on top of that brick and hit the ?-mark block above to get another coin. You can break bricks up here too if you want some more points.
To the right, there is a ?-mark block that contains a Starman. If you get a Starman, you start flashing, and you're temporarily invincible. If you touch any enemy while invincible, it will be defeated. To the right, there is a turtle, also known as a Koopa Troopa. The three ?-mark blocks on the bottom just have coins, but the one on the top has a Mushroom if you're regular-sized Mario or a Flower if you're Super Mario.
To the right of that, there are several Goombas. Then there are some ?-mark blocks above that just hold one coin each. Go to the right, jumping over the stairs, but be careful not to fall into the pit between the second pair of stairs. Go to the right and you will reach a green pipe.
World 1-1 Part 2
If you went into the secret area, you will come out of the green pipe mentioned in the previous paragraph. Go to the right, break the bricks if you feel like it, and hit the ?-mark block to get a coin. Get past the two Goombas on the right, then jump up to the top of the stairs and stay there. You'll see a flag pole to the right (also known as the goal pole). You get more points the higher you are when you touch the flagpole. In addition, if you hit the flagpole when the last number of the countdown timer is 1, there will be 1 firework; if you hit the flagpole when the last number of the countdown timer is 3, there will be 3 fireworks; and if you hit the flagpole when the last number of the countdown timer is 6, there will be 6 fireworks. You get 500 points per firework.
So, hold the B button, then jump to the right to try to touch the flagpole as far up as you can (or just jump onto it from any height if you don't care about a high score), and try to time it correctly to get the fireworks bonus mentioned above if you feel like it.
Afterward, you will move on to World 1-2.