New Super Mario Bros./World 2-1

Welcome to World 2, a harsh desert with an interesting variety of enemies and terrain. Not many plants can survive in the arid sand, but Pokeys do thrive here. These living cacti can grow very tall, and trying to stomp them will only result in prickled feet. Bring a Fire Flower or Blue Shell to attack them directly, avoid them completely otherwise.

Level walkthrough
Shortly after the level starts, you will encounter the first Pokey of the level, the main threat in this course. Their danger is obvious, as they can grow pretty high, and their spikes mean you can't jump on them as a method of attack. Instead, you must use a fireball or the Shell Dash to knock pieces of them off. If you manage to hit the head of a Pokey, you instantly defeat the whole creature, a feat easier to achieve with the Fire Flower. If you find yourself without a weapon to use against these cactus monsters, simply use any platforms available nearby to evade them. For this first Pokey, you simply have to jump from the blocks over it, following the path of the coins. After the first Pokey is another new enemy, the Spiny. You also cannot stomp on this little spiked creature, and while this Spiny is alone, you will encounter a lot of them very soon. The second Pokey is right next to it, near a yellow block with a face. Hit the block to make another block pop out on top. Do this until you get a vertical platform high enough to let you leap over the next Pokey.

Up a slope beyond the second Pokey is the first Star Coin, as well as the third Pokey. Don't rashly jump for the Star Coin immediately. Instead, wait for the Pokey to move as far down the slope as possible before making the jump. For the following Pokey, use the moving platform to the left of it as a jumping spot if you can't defeat it directly. After that, you must dodge two Pokeys by jumping over them as the platforms they are on descends deep enough into the pit. Quickly dash forward to nab the second Star Coin a bit further ahead. If you're too slow, a platform carrying the Pokey will descend to the ground, making collecting the Star Coin difficult. Watch out for the quicksand around the Star Coin, as they will impede your jump height, and even potentially kill you if you get pulled too far in. The next Pokey is a bit tricky to both dodge or kill. Both you and the Pokey will be on moving platforms that have different speeds over a bottomless pit. Take your time to get a feel for the movements of the platforms so that you can jump at the ideal time to evade the Pokey. Make it past that Pokey and you will trigger the checkpoint.

One of the blocks shortly after the checkpoint flag contains a power-up. Right after that is another section with Pokeys. There is only a lone Pokey here, but you can observe an odd feature of these monsters. When a moving platform overlaps with the ground they're standing on, they can shift on to the platform instead, and vice versa. This quirk becomes more important in the following section, where you can see the third Star Coin on a small platform. There are two Pokeys surrounding it, any of which can cover the Star Coin once they get on the moving platforms. You must be quick and precise with your jumps to land on the platform with coin. If you do it fast enough, you can get it before the Pokeys arrive on the platform, but it is advisable to collect it only after you've defeated the Pokeys one-by-one instead. After that section is a tiny Warp Pipe that can only be accessed by Mini Mario. It leads to a bonus area with 36 coins, not a particularly tempting secret considering you need to be Mini Mario for much of the level, but you can go for it if you happen to have a Mini Mushroom in reserve. The penultimate Pokey of the level is even more tricky to cross, as you have to continuously jump between two sets of moving platforms until the Pokey moves low enough for you to clear it. Beyond the Pokey is a pipe which takes you to the flagpole. Hit the middle block once you exit from the pipe to reveal a P-Switch. Hit the P-Switch, then jump on to the blocks over the last Pokey and to the flagpole.

Star Coins

 * 1) In the air around the third Pokey. Time your jump to nab it while leaping over said Pokey.
 * 2) Over the quicksand section, below a Pokey on a moving platform. Grab the coin before the platform descends.
 * 3) On a platform over a bottomless pit. The nearby moving platforms can shift a Pokey on to the platform with the coin.