Super Mario Bros. Gameplay
Super Mario Bros. is divided into eight worlds, each of them containing four levels. Mario has to get to the end of the level by jumping over various gaps and avoiding the enemies on his way. He can use several platforms (some of them collapse when Mario lands on them), stairs in the level, as well as jumping boards. There are also pipes along the way, some of which Mario can enter to visit various secret coin rooms before returning to the level, a bit further ahead than when he left.
Enemies include Little Goombas, Koopa Troopas, Buzzy Beetles, Koopa Paratroopas, Bullet Bills, Hammer Brothers, and leaping Cheep-cheeps. All these enemies can be defeated when Mario jumps on them. Koopa Troopas and Buzzy Beetles cower in their shell when jumped on, which Mario can kick to defeat other enemies with. Koopa Paratroopas lose their wings and fall to the ground when Mario jumps on them. Other enemies include Piranha Plants, and the Spiny-throwing Lakitus, and Mario has to either shoot fireballs at them or just avoid them. Two levels take place underwater. In the water, Mario can swim freely from the top to the bottom of the screen. The enemies in underwater levels are Bloobers and Cheep-cheeps. Mario can only defeat these creatures by shooting them with fireballs.
If regular Mario takes a hit, falls down a pit, or if the Time Limit runs out, he loses a life and restarts the level. The point where Mario continues depends on how far he ran through the level before getting defeated; either from the beginning or at one of several invisible "checkpoints" throughout the level.
Mario can get special power-ups out of ? blocks or, uncommonly, bricks. Most of the ?s in which Mario can find these items are visible, but some are hidden and only become visible when Mario hits them from beneath. With the Magic Mushroom, he turns into Super Mario. As Super Mario, he can survive the hit of an enemy one time, at the cost of turning back to regular Mario. He may also destroy empty bricks by jumping beneath them. Additionally, he can also get the Fire Flower. With the Fire Flower, Super Mario turns into Fiery Mario, which allows him to shoot fireballs at enemies to defeat them from a distance. With the 1 up Mushroom, he gains an additional life; he can also get an extra life if he collects a hundred coins. With the Starman, which can only be found in bricks, Mario turns invincible for a short amount of time and can defeat enemies by simply touching them. With the exception of coins, only one item can appear on the screen, and when a new item appears, the previous one will disappear.
At the end of each level, a castle stands with a flagpole nearby. When Mario reaches the flagpole, he takes down the enemy flag and enters the castle, completing the level. The higher the spot that Mario hits the flagpole, the more points he receives.
The fourth level of each world plays inside a castle. They are usually filled with Fire-Bars and Podoboos. At the end of a castle level, Mario is confronted with a fake Bowser in Worlds 1 through 7 and the actual Bowser in World 8. Mario ordinarily have no way to hurt the fake Bowsers or the actual Bowser and have to either use the ax to destroy the bridge, causing either the false or real one to fall into the lava, or pelt him with many fireballs, which produces the same result and reveals the true forms of the fakes. After defeating an impostor, Mario frees one of the seven remaining mushroom retainers from the castle, at which point they say their iconic phrase: "Thank you, Mario! But our princess is in another castle!" At the end of the castle in World 8, Mario frees the grateful Princess Toadstool and completes his adventure.Source: https://www.mariowiki.com/Super_Mario_Bros.