Stage 3-1
---------

In the opening stage of this watery world, go right and down the pipe. When 
you reach the underwater area, swim to the right and avoid the large and 
small Cheep Cheeps you encounter. If you hit the first couple of blocks, you 
can get an item (if you are Fire Mario here, this level will be a breeze).

You can swim through a Red Ring in the upper area and collect some Red Coins 
for a 1-Up. Further ahead, when you pass the midpoint, you will find a mixed 
item box; hit it when the item you want appears and you will get it. Continue 
right past some more fish enemies, and you will see some pipes blowing air 
upward. When you reach the formation of 3 pipes, the middle one will not be 
blowing air, so drop onto it and go into the room below. Swim to the right in 
this coin bubble room, and collect Star Coin #1.

Go up the pipe to exit this room, then continue to the right. You will spot 
Star Coin #2 up above, so swim up to it from below, being careful not to get 
pushed away by the air coming from the pipes. Try your best to avoid the blue 
fish which will home in on you and try to eat you; fireballs are your best 
bet here.

Keep going right and you will find an upside-down P switch; hit it to turn 
the blocks into coins. Then, quickly swim to the right and up to get Star 
Coin #3 before the coins revert back to blocks. Ahead is a more difficult Red 
Ring/Coin layout, followed by the exit pipe. Go up the pipe to reach dry 
land, then all that's left is for you to jump to the flagpole and exit.


Stage 3-A
---------

Here, you will be able to swim around in the water as well as jump along dry 
land. Head to the right, stomping on the water spiders along the way. There 
is a Red Ring under the water if you want to check it out. Keep going right 
for a while until you reach an area where there are outlines of blocks in the 
air, and a ! switch underwater. Hit the switch, then jump out of the water 
and onto the red blocks so you can reach the upper-right area.

From there, go right and defeat a Koopa Troopa on the platform. Drop into the 
water to the right and you will see a bunch of blocks, and a water spider 
dropping bombs to clear said blocks. Move around to clear the entire area 
while you avoid getting hit yourself, then collect Star Coin #1 when you are 
able to.

Swim to the right and hit the underwater block to get a Mini Mushroom. Go 
back up to the surface and jump onto the barrels. Bounce off the back of one 
of the Koopa Troopas to obtain Star Coin #2 high above. Run across the water 
to the right until you reach the pipe. Go through the pipe to reach the next 
area of the stage.

In this next area, go right across the water and go into the first upside-
down pipe you see. There, run across the water and jump to get Star Coin #3 
above you. Go down the pipe at the other end, then continue to the right 
while avoiding the water spiders. Jump across the spinning ledges to the exit 
pipe, then go into the pipe and head right to the flagpole.


Stage 3-2
---------

In this fairly simple area, make your way to the right by going across the 
wobbling mushroom platforms and stomping Goombas along the way. When you 
reach the elevator platforms, jump from them to collect coins, then continue 
right to the midpoint. Go down the yellow pipe and head right to collect Star 
Coin #1 when the platform tilts high enough for you to jump.

Go up the pipe at the far right to exit this room. In the main area again, go 
right and jump across a series of elevator platforms. At the end, jump to the 
high ledge to receive Star Coin #2. Continue to the right and you will reach 
a giant wobbling mushroom platform that moves to the right as you stand on 
it. You will spot red, yellow, and green pipes overhead.

If you want to go for the secret exit, go up the green pipe, then down the 
right pipe. In the following room, jump across a series of wobbling mushroom 
platforms to reach the secret flagpole leading to Stage 3-B.

If you aren't going for the secret exit though, simply ignore the colored 
pipes overhead. When you reach the regular platforms again, jump onto them. 
Go through a Red Ring if you want, otherwise continue to the right and onto 
another wobbling mushroom platform.

Head to the right while on this platform, and you will see a Paratroopa in 
the air. Try not to kill it early on; instead wait until you see Star Coin #3 
above, then bounce off the enemy's head to reach it (make sure your platform 
is in reach though). You can probably jump to reach it from the platform if 
the tilt is sharp enough. Continue to the right and jump onto the solid 
ground, and the flagpole will be up ahead.


Stage 3-B
---------

In this pipe-filled stage, you will have to deal with plenty of Piranha 
Plants as you progress. If you are Fire Mario, you will once again have an 
easy time getting through this. Anyway, make your way to the right while 
hopping from pipe to pipe, evading the plants if you have to. Up ahead you 
will find a star coin in an enclosed area below your feet.

To reach it, continue to the right and you will find a whole series of pipes. 
Go down the low red pipe, then head left through the room you turn up in. 
Avoid the plants and go up the other red pipe to emerge, collecting Star Coin 
#1 in the process. Go back down and hit the mix item box, then go right and 
up the first red pipe once again.

Back in the pipe maze of sorts, go right and jump onto a yellow pipe. When 
the coast is clear, jump to the next green pipe. Wall jump between the pipes 
above you to reach the alcove to the right, where Star Coin #2 is located. 
Jump back around to reach the lower area, then continue to the right in the 
same fashion, being cautious of the Piranha Plants.

Towards the end, you will find Star Coin #3 below one of the pipes, which you 
can easily access. From there, simply go right to the flagpole.


Stage 3-C
---------

Here, you will have to deal with that giant fish that jumps out of the water 
again. If you are Fire Mario, you can shoot it down each time it appears to 
help yourself out. Either way, head to the right by jumping from platform to 
platform. Be careful because some of the smaller platforms (you'll know them 
when you see them) will fall when you step on them). Go right and sink with 
the smaller platforms to collect Star Coin #1.

Continue to the right and you will have to deal with flying Cheep Cheeps. At 
least there will be plenty of coins in the air to collect. Pass the midpoint 
and you will reach a structure with Star Coin #2 under it. If you can kill 
off the big fish, it will make things much easier for you right now. Go into 
the water and swim under the coin, then jump up to get it before swimming 
back out from under this structure.

Go right and hit the upside-down P switch to turn the coins into blocks, and 
to make some blue coins appear in the air. Go right quickly and hit the ? 
block to receive a Starman, then quickly dash/jump your way to the right. 
When you reach the platform of blocks (hopefully before they turn back into 
coins), jump into the red upside-down pipe. When you emerge, fall with the 
platform below you to get Star Coin #3, then go right to the flagpole.


Tower
-----

When you enter, you will see 3 pipes on the floor in front of you. The middle 
one is the only working one, and it will shoot you upward to the fences. 
Don't grab onto the upper fence yet though; wait until you fall to the second 
one, then grab onto it by pressing Up. Climb to the left, then jump to the 
upper-left fence. Defeat some Koopa Troopas by hitting them from above or 
punching through the fences when they are at the other side. When you get to 
the top, jump to the upper ledge and jump again to get Star Coin #1.

Drop back down to the ground and use the middle pipe to launch a second time. 
This time, grab onto the fence at the peak of your shot. Make your way to the 
top fence, then punch through to flip around to the opposite side. Take note 
that until you hit another flip panel on the fences, you will be behind the 
fences.

Jump onto the regular platforms above and go left, then climb the fence and 
get to the ledge above. Go left and jump on the Koopa Troopa, then jump and 
toss its shell to the block wall to the right. Slide under the opening and 
jump to break the left half of that wall. Wall jump to the room above where 
another flip panel is located. Go to the right side and climb onto the fence, 
and punch it to flip back to the front side. Drop down to the left and 
collect Star Coin #2 now that you are able to do so.

Next, go back right and wall jump to the fence you can flip around. Go right 
and jump to hit the blocks above you, then enter the door there. In this tall 
room, hit the ! switch to make red blocks appear in the room, but get ready 
to move fast! Hold B and jump, then quickly climb/jump your way through this 
room, while avoiding the Koopa Troopas on the fences. If you make it to the 
top on time, grab Star Coin #3 and enter the next room.

In the final room, jump up and left, and go through the door to meet Bowser 
Jr. There is water below the battle platform that you can fall into, but you 
shouldn't really worry about that. Pounce on Bowser Jr. 3 times to win, as 
usual.


Stage 3-3
---------

Here, go right and down the green pipe to enter this underwater stage. Down 
here, you not only have to outmaneuver Cheep Cheeps, but the Bloopers as 
well. They can get annoying, so hopefully you have a Fire Flower in store for 
this stage. Swim to the right, collecting coins and hitting the blocks along 
the way, while avoiding the enemies. Up ahead, you will reach a green pipe 
followed by what appears to be a pit. Sink all the way down that pit and you 
will find a hidden room with Star Coin #1 to the left.

Also in this deep pit is a ? switch. Hit it and all the pipes to the right 
will stop shooting air bubbles for a limited time. So, swim back up and go 
right, and downward. Swim through the Red Ring if you want, otherwise keep 
going to the right. You will see a series of pipes forming steps; go down the 
third pipe and you will enter a large coin room. Swim to the bottom-right 
corner of the room to find Star Coin #2.

To exit this room, get to the upper-right area. Swim your way upward through 
the currents, and continue to the right. You will see an arrow sign pointing 
at the upside-down pipe above you. Before you go there though, sink to the 
bottom area through the currents, and collect Star Coin #3. Be quick to swim 
back up since 4 Bloopers will appear as soon as you grab the coin.

Go back up to the top and through the upside-down pipe. Once outside on dry 
land, simply jump up the pipes and leap towards the flagpole to exit.


Ghost House
-----------

In this house full of Boos, head to the right. When you reach the steep hill, 
take the lower path and hit the ? switch to make steps appear. Jump up the 
hill and slide down the other side. As a note when dealing with ghosts: if 
you turn your back to them, they will approach you; face them and they will 
turn away. With that said, continue right. Go into the door you see and hit 
the blocks inside to find a Boo and an item (Mushroom/Fire Flower).

Leave the room and continue going right until you reach the platform that 
moves up and down. Enter the door to the right of it for now, and bounce on 
the pumpkin enemies to grab Star Coin #1 in the air. Exit the room and wait 
for the platform to come down. At that point, hit the ? switch and ride the 
platform upward. Quickly jump to the steps to the right, then go up them and 
jump to the upper-left steps. If you reach the top before the steps retract, 
you will be able to claim Star Coin #2.

Go back down and hit the switch again, but this time, continue to the right 
from the first set of stairs. Go right and down the hill, then turn left at 
the bottom. Hit the block to reveal a ? switch; hit it to make a door appear 
above you. Go back right and up the steps, then drop down and head through 
that door.

NOTE: If you want to reach the secret exit that leads to the Cannon, follow
      these instructions. Hit the last ? switch in the room, then quickly go
      right and wall jump against the right wall to reach the stairs slightly
      quicker. Jump up the steps and hop to the left, and go down the next
      set of steps fast. Once at the bottom, go right and you will see two
      doors. Go into the left door and you will end up at the secret exit's
      flagpole.

In the new room, first jump up the ledges to the left and you will come to a 
mixed item box. You will need to be Shell Mario for the next part, so try and 
stop it on the Blue Shell (if you are unsuccessful, come back later to do 
this). Drop down to the lower area and head right to the ? switch. Hit it and 
jump up all the stairs to the very top. Once there, if you are Shell Mario, 
run and slide in shell form through the blocks to the right, then continue 
through the opening to get Star Coin #3.

When you're done here, go through the door. Now that you are outside of the 
ghost house, jump up the blocks to the right and leap towards the flagpole to 
exit this stage.


Castle
------

In the first area, there will be a series of giant spiked columns that come 
crashing down from the ceiling before retracting. Stay back and wait for the 
first column to go up, then jump across to the next safe ledge. Up ahead you 
will see Star Coin #1 in a small alcove below; when the spiked columns go up, 
drop down to get the coin, then stand there and wait for the column to come 
down and go up again.

Continue to the right as you have been, then hit the block at the midpoint to 
get an item. Go right, being careful of the Whomps (when they fall, ground 
pound to defeat them). Climb the rope and keep going to the right for now. 
Hop across the donut blocks in the water, then jump onto the rope hanging 
from the ceiling. Swing to the left ledge and wall jump through the hole in 
the ceiling. Up there, go left and drop down to get Star Coin #2, which you 
passed up earlier.

Now, go back to the right and swing from the second rope once again. Jump 
over the giant Whomp and jump across the donut blocks when the spiked column 
goes back into the water. On the next platform, hit the block to get an item, 
then wait for the passage ahead to clear up before dashing/jumping through 
it. It is possible to clear the entire path if you run and jump straight 
through without making mistakes.

When you make it to the end, you will see the red boss door. Don't enter it 
at first, instead wait for the spiked column to the right to go back upward. 
Then, slide under the wall and swim against the left wall until the column 
goes down and up again. As it goes up, jump to the upper ledge and then onto 
the high ledge with Star Coin #3 on it. When it's safe to leave, go back down 
and left, and enter the boss's door.

In here, jump over the water pit and go right to face the giant Cheep Cheep 
boss, Cheepskipper. The large fish, as well as 3 regular-sized Cheep Cheeps 
will be swimming around below, periodically jumping out to hit you. The 
battle plan here is to move around and wait for the giant Cheep Cheep to jump 
out, then you have to jump on its head to cause damage. Do this 3 times to 
win the fight.

With the fight over, collect the golden boss key and you will be on your way 
to World 5 (or you can select World 4 on the touch screen if you unlocked 
it)!