This level takes placed mostly underground. The player starts above ground and walks through through a pipe. Underground, there will be two Little Goombas and five ? Blocks, with the first one holding a Magic Mushroom or Fire Flower. The other four contain coins. Following this is a block tower structure, where a Little Goomba strolls by, and there is a Brick Block holding ten coins. Further on are some Brick Blocks, one of which holds a Starman and some coins, with two Koopa Troopas below them.
The player will then approach an area filled with Brick Blocks, with a Koopa Troopa and five Little Goombas. By breaking the blocks, the player can reach and walk across the top of the level. There will also be a Brick Block with a power-up and a hidden 10-Coin Block. The player will eventually come across a pit and, followed by a block platform that allows the player to obtain a 1-Up Mushroom. There will then be two Little Goombas and three pipes, all of them with Piranha Plants inside. The first pipe leads into a secret room where the player can collect coins and strike another 10-Coin Block.
The player can exit the area by a Warp Pipe in the far right. This pipe leads to the third one in the main area. There are two gaps, with two ground blocks and some Brick Blocks in between. What follows is a small, pyramid-like structure with two Little Goombas. Further up are some lifts that move in a vertical direction. The first one moves downward while the right one moves upward. Lying between them is a platform with a Koopa Troopa and some Brick Blocks, with the final block on the right holding a power-up. There is a pipe that leads to the final area. The lifts can be used to help the player access the top path that leads to the hidden Warp Zone. The Warp Pipes are arranged from right to left. The first pipe leads to World 2, the second one leads to World 3, and the third one leads to World 4. If the player enters through the regular pipe, they will be lead back to the overworld, where there is a pipe containing a Piranha Plant. What remains is the staircase with the flagpole right after it.
Challenges in Super Mario Bros. Deluxe
Note: The Warp Zone has been altered to include several Brick Blocks, three ? Blocks, some coins, and a power-up before the pipe leading the flagpole.
Red Coin locations
- Red Coin #1 is located within the first row of blocks, inside the last block to the right.
- Red Coin #2 is located above the brick formation, along with three regular coins.
- Red Coin #3 is located on top of the large block pillar, located right after the second power-up.
- Red Coin #4 is located within the secret area, hidden inside the 10-Coin Block.
- Red Coin #5 is located right above the stone stairs, right before the descending platforms.
Yoshi Egg location
- The Yoshi Egg is found at the very end of the underground bonus area, inside a Hidden Block above the exit pipe.
- World 1-2 reappears in every remake of Super Mario Bros.. One level in Super Paper Mario is based on World 1-2. In Super Smash Bros. Brawl, the Mushroomy Kingdom stage sometimes takes place at World 1-2. At other times, it takes place at World 1-1.
- It appears in WarioWare: Twisted! in 9-Volt's microgame, Super Mario Bros. for the second level difficulty. It reappears in WarioWare Gold, in 18-Volt's microgame, which is the same name for second level difficulty.
- The player can use a glitch to make the warp zone also lead to World 5 and the Minus World.
- In the chapter "The Bitlands" from Super Paper Mario, there is an underground area that is nearly identical to this level. However, the Warp Zone transports the player to other sections of the area, not to other worlds.
|Characters||Protagonists||Mario • Luigi|
|Supporting characters||Bowser • Fake Bowser|
|Supporting characters||Princess Toadstool • Mushroom Retainer|
|Enemies||Enemies||Blooper • Bullet Bill • Buzzy Beetle • Cheep-Cheep • Firebar • Goomba • Hammer Bro. • Koopa Paratroopa • Koopa Troopa • Lakitu • Piranha Plant • Podoboo • Spiny|
|Items||Items||1 up Mushroom • Coin • Fire Flower • Magic Mushroom • Starman • Poisonous Mushroom|
|Worlds||World 1||World 1-1 • World 1-2 • World 1-3 • World 1-4|
|World 2||World 2-1 • World 2-2 • World 2-3 • World 2-4|
|World 3||World 3-1 • World 3-2 • World 3-3 • World 3-4|
|World 4||World 4-1 • World 4-2 • World 4-3 • World 4-4|
|World 5||World 5-1 • World 5-2 • World 5-3 • World 5-4|
|World 6||World 6-1 • World 6-2 • World 6-3 • World 6-4|
|World 7||World 7-1 • World 7-2 • World 7-3 • World 7-4|
|World 8||World 8-1 • World 8-2 • World 8-3 • World 8-4|