World 1-2 (New Super Mario Bros.)

World 1-2 is the second level of World 1, and subsequently, of New Super Mario Bros.. Completing this level through the normal exit will unlock World 1-3, whilst exiting the level from the secret exit will give the player access to.

Layout
The level begins with Mario ground pounding into the underground cave. Many Goombas and Koopa Troopas are found in this cave. Mario encounters some ? Blocks. Hitting them produces Coins. Mario collects them and moves on to the first Star Coin. He can jump onto the ledge, and collect it. He can also Ground Pound on some brick blocks to collect a bunch of coins. He then moves on, encountering more Goombas. Going forward, Mario finds a block of rock that he can get through by smashing the brick blocks above it. An abyss is found, which Mario can jump over it, followed by the second Star Coin, surrounded by some brick blocks. Mario can collect the Star Coin by ground pounding the blocks above it. A Piranha Plant is then met. Mario jumps over it and goes down the pipe it was guarding. Mario encounters some Coins, and a Koopa Troopa can be used to break some brick blocks, creating a passageway. Mario crawls under the passageway, where some Goombas are found. Running, he then sees a ? Block, which contains a Mega Mushroom. Mario can use it to destroy all the Goombas and brick blocks. He then goes up a pipe nearby, leading him back to the main cave. He must jump over some pipes sticking out of an abyss. He then makes it onto the ground and runs forward. He then meets a tilting log. He runs over it, and continues through the cave. A pipe is found at the end, which leads outside, near the flagpole. He then finishes the level. There is an Super Star above the first Brick Block after the first Piranha Plant.

Secret Exit
Towards the end of the level, there will be a small gap that Mario can access with the help of the log-like platform. Running across the gap will lead to the third star coin and a pipe, which will lead to the alternate exit. Using the secret exit unlocks a different path that directly leads to a secret Toad House and the tower of that world.

Star Coins

 * Star Coin 1 - In the beginning of the level, it can be found on a ledge that needs the use of Brick Blocks to get it.
 * Star Coin 2 - A huge plethora of blocks surrounds this coin. Ground pounding the top of the box will reveal an opening.
 * Star Coin 3 - On the way to the secret exit, the Star Coin should be in plain sight.