New Super Mario Bros. 2: Mushroom-Cannon

This level features crows and Boomerang Bros. You'll have to bounce off some crows with precision, so this may take a few tries. The cannon will take you to Flower World.

Coin Total: 64,088

New Super Mario Bros. 2: Mushroom-Castle

This level takes place on stone blocks over spikes. A giant spike ball destroys the floor, so move quickly and carefully. Trip the Thwomps and jump over them. Pound the brick blocks over the first Star Coin to reach it. Jump over the Whomps, or defeat them if you like. At the end, you'll see a green pipe. Before you take the pipe, go to the right for the second Star Coin. The green pipe leads to the midpoint. The pipe below will take you to the next stage, which is similar to the first. There are rotating brick blocks here and skulled Piranhas. At the end, get enough of a running start with the Raccoon Tail to fly over the boss door for the third Star Coin. Approach the area from the left. This world's boss is Larry Koopa. There are pillars appearing from the ceiling and floor in an alternating pattern. The pillars will allow you to reach the platforms above and will limit Larry's movements during his shell cycle. Three hits will defeat him and the key will appear. The path will open to World 3.
Coin Total: 57,272

New Super Mario Bros. 2: Mushroom-3

This level has Buzzy Beetles and POW blocks. Once you go past the first two POW blocks, the level will start automatically sidescrolling. Go across the infinite platforms moving up and down and you'll come across the first Star Coin. It is above a donut lift below a fire pipe, which will give you three 1-ups if you're fast enough to reach them. There is a ? Switch between two yellow pipes. It makes coins from both of them. At the end is a yellow pipe. The POW block to the right of the pipe which makes coins. The pipe takes you to the midpoint, where the POW block allows you to get four items, either Super Mushrooms or Fire Flowers. Go through the next pipe and the level starts scrolling again. Jump left from the infinite platforms for the second Star Coin. Use Buzzy Beetles to hit the next POW blocks for the third Star Coin. The rock wall will drop, revealing another fire pipe. It will give you a Mega Mushroom, so run to the right for lots of coins. The pipe at the end will take you to the flag.

Coin Total: 56,391

New Super Mario Bros. 2: Mushroom-B

This level features a lot of vines. Either climb the vines or hop up the mushroom platforms to reach the green pipe. The level will start automatically scrolling up. There is a Chomp to the left. Hop up the mushrooms and hit the POW blocks to make vines appear. Climb up the vines past the circling coins. Stay to the right to climb the vine to the next mushroom platform. There are two brick blocks to the left. Jump on them for the first Star Coin. Above the Chomp is a POW block that makes four vines appear. To the right is the second Star Coin. Just above it is the midpoint. Hit the POW blocks for vines and you can get some Red Coins. Kick the Koopa shells between the brick blocks and activate the Gold Ring for coins. The brick blocks have vines in them. The third Star Coin is between the middle two vines. Carefully climb up the next set of vines towards the middle to avoid the Chomps. Hit the block over the Chomp on the left near the green pipe for a vine through the gap in the ceiling. It allows you to bounce off a Parakoopa before landing on the flagpole. This opens the path to the cannon.

Coin Total: 55,922

New Super Mario Bros. 2: Mushroom-Ghost House

This Ghost House is a maze of doors. Use the Raccoon Leaf to reach the Gold Ring above. The Boos will float away, trailing coins behind them. Some parts of the level have Gold Rings. The door to the right leads to a room with some coins and six ? Switches. The switches are in two sets of three. Hit the left switch of the lower set to make a platform appear, so you can reach the higher set. Hit the left switch there to make the blocks in front of the coins disappear. Hit the right switch of the lower set to make a door appear and hit the middle switch of the higher set to make a platform appear underneath it. The left door in the first area leads to the first Star Coin. Hit the right ? Switch to make platforms appear to it. Let that switch run out and hit the switch to the left to make a door appear and some platforms to reach it. Both doors will lead to the second area, which has a random coin block high above. The middle door leads to a room with the second Star Coin. Move towards the center of the room to activated the diamond springs. This will make Mario bounce around. Go to the left side and hit the switch to make the second Star Coin appear below, but you'll have to backtrack. The switch will make the door appear, as well. Stand on the platform over the door at the top of the stairs to make coins appear. Go through the door at the top of the stairs. This will lead to a room with three switches and three paths. Hit the right and middle switches to reach the top path. Fly up the second gap in the ceiling and hit the ? Switch to the left. Drop down and fly up the first gap before the switch runs out to get the third Star Coin. Hitting the swith again will make a door appear to the right. This leads to the Red Goal. Hit the middle brick block behind the giant Boo for a ? Switch to make blocks to the flagpole appear. This leads to Mushroom-B. In the last room with the three switches, hit the left and middle switches to access the middle path to the regular goal to Mushroom-3.

Coin Total: 54,699

New Super Mario Bros. 2: Mushroom-A

This level is filled with ice and spike balls. Let the first spike ball pass you. As you ascend, some spike balls will not go away. The first Star Coin is blocked by brick blocks. A spike ball will take care of those for you. Wait for it to roll to the right side before running and sliding to get it. Above is an area with an endless supply of spike balls that roll off-screen. Stay to the right and jump up on the right side to get the second Star Coin. Above it is the midpoint. There are some Red Coins ahead. You'll see two spike balls guarding the third Star Coin. Hit the ? Switch above to make a giant spike ball take them out. Be careful above getting the Star Coin, as the giant spike ball doesn't go away. Go through the blue pipe to reach a random coin block. Once back in the main level, go immediately to the left side to dodge the giant spike ball destroying the overhead brick blocks. Let a spike ball pass, then slide on the donut lifts, then duck to reach the blue pipe at the top. It leads to an icy staircase to the flagpole.

Coin Total: 58,858

New Super Mario Bros. 2: Mushroom-2

It's time to go swimming again. Go through the green pipe and start the level. It's an automatic sidescroller with Urchins and rock that will move out of the way rather slowly. A Fire Flower is great here to destroy the Urchins. The path will briefly fork near the floor, so drop down to reach the first Star Coin. You will be temporarily trapped until the rock in front of you moves. Next, the rocks in the floor will rise to alter the path the Urchins will take. This will lead to the midpoint and a random item block with a Gold Flower. There are some Red Coins nearby, but you need to deal with Urchins to get them. As you progress, you'll find Urchins trapped by rocks that are released from above and below. Be careful here. Swim up into the second alcove once the Urchin descends to get the second Star Coin. Immediately after that area, go through the green pipe above. Quickly swim up to avoid giant green Cheep-Cheep and get the third Star Coin at the top before rocks close in over it. Go through the green pipe to reach the flagpole. If you have a Gold Flower and do not go through the green pipe to the third Star Coin, you'll find a blue pipe blocked by brick blocks. It will take you to an area with brick blocks so you can make lots of coils. It will lead you to the same flagpole.

Coin Total: 54,400

New Super Mario Bros. 2: Mushroom-1

It's a new world. This particular level has lots of coin potential. The first brick block can become a Gold Block. Platform over the colorful blocks until you reach a blue pipe. Hit the invisible block next to it on the left for a Starman. Take out some Koopas and Piranhas, then hit the item block to the left of the midpoint for another Starman. Go down the yellow pipe in the center. Pound the POW blocks to form stairs down to the first Star Coin. If you don't feel like dealing with the Parakoopas, just send a shell down to get the first Star Coin for you. Go through the red pipe back to the main level. To the right are more block platforms. On top of the right tower is a Gold Ring, so you can cash in, especially if you have a Starman and a Gold Flower. Between the next blue and red pipe is a yellow pipe and a Red Coin Ring. The yellow pipe takes you to an area with lots of brick blocks. Instead of pounding them, hit the item block for a Gold Flower and get some coins. Don't destroy all the blocks at once so you can reach the second Star Coin, which is blocked from above. Next, you'll see some tall block platforms. You can try bouncing off the Koopas to reach the top, but I recommend flying. You might have to return with a Super Leaf. The third Star Coin is on the right tower. Go to the left tower and hit the invisible block for a vine to an area with flying blocks. Hit the block that isn't flying to make it fly. Go over the brick blocks and hop on the flying item blocks to reach the Red Goal. This opens the path to Mushroom-A. Otherwise, continue to the right on the main level to reach the regular goal to Mushroom-2.

Coin Total: 58,686
I found the secret goal after completing other levels.