World 1-2 is the second level of Grass Land in Super Mario Bros. 3 and its remakes Super Mario All-Stars and Super Mario Advance 4: Super Mario Bros. 3. The player is given a time limit of 300 seconds to complete it.
This level is set within a grassy environment. The player begins at the base of a hill, which has a sideways pipe at the top that infinitely spawns Goombas. A ? Block lies on the other side, and it holds a power-up. By using the block as a platform, the player must leap over the two pipes that form a "T" shape. The top pipe also spawns Goombas continually.
A group of coins lie at the bottom of the next hill, along with a Switch Block inside a Brick Block underneath the floating Warp Pipe, with a Hidden Block containing a 1-Up Mushroom above. This pipe leads to a secret area, where the player can collect twenty coins. They will then be lead outside through a pipe a few inches back.
Pushing ahead, the player will find two Jump Blocks, the second one containing a power-up. Another hill follows, leading down to a pipe, followed by three more Jump Blocks, which will help the player avoid the small pit below. The third and highest Jump Block contains a Starman power-up. Ahead is another short hill with two more pipes. One last hill awaits, leading the player to the goal.