Here, in World 3-1, it is an overworld setting, but, more obviously, day has turned to night. This change in time changes nothing about the gameplay, however.
The first two Q blocks contain coins, while the last one contains a power up. You'll also start to see Green Paratroopas now as well. These guys, instead of just flying, jump along the ground, and can be slightly problematic.
We got a couple of pipes here, with Piranha Plants inside, as well as a Goomba in between them. (That pipe over there on the right that you can barely see will lead you to Coin Room C).
Getting over the pit shouldn't be a problem, just be wary that you don't hit those Goombas by accident.
Another pipe, with a Piranha Plant, and a red herring brick. (Just about every pipe from now on will have Piranha Plants in them).
Another Troopa to avoid, with another pipe.
This bridge here is rather interesting as it only serves as decoration. Those Goombas however are quite important. If you kill only the last one in line, you will have the opportunity to get an extra life.
If you only killed the last Goomba, the one up is in an invisible block that is next to the cloud on the right.
The first brick contains a star, which can be very helpful in something coming up.
The Goombas and Troopa can easily be taken care of, but the Piranha Plant has to either be avoided, or taken care of by invincibility.
Right here is the first instance of a Hammer Bros. These guys can run around, jump, and through multiple hammers at you with great precision, so they are worth 1000pts.
Jumping on them is risky, so avoiding them, shooting them with fire balls...
... or breaking the brick they're standing on is the best way to deal with these guys.
Here, you have two options. Option 1 is that you take the springboard to the top and move on with your life. Option 2, on the other hand, requires you to jump while running to get in between the bricks. (Doing option 2 allows you to hit the right most brick on the top, revealing a vine to take you to Coin Heaven B).
Be careful of the Goombas coming down the stairs. Either try and jump over them, or take them out one at a time.
The first Troopa shouldn't be an issue, but be wary of the second one as Green Troopas fall off edges.
There are also three Goombas to deal with.
The Q Block Mario is by has a power up. The rest have coins.
Three more Paratroopas, as well as a regular Troopa to contend with.
Getting on and jumping from there isn't too much trouble...
...but there are two last Troopas to deal with.
"Experts can get unlimited lives by jumping on the Troopa while it's on the edge of the step. Then, by repeatedly jumping up and down on top of the shell, you can garner lots of points, and get lots of lives in the process.
The flag, and on to World 3-2.
World 3-2 is technically another Overworld setting, but can also act as an Athletic setting for those who konw the level well.
Most of the level is quite flat, and can be easily completed by just running through it, avoiding the enemies in the process.
The athleticism comes from how fast you can complete the world, and how many points you can get from defeating enemies. The first enemy you come upon is a Troopa, and by jumping on the Troopa twice, you can propell the shell forward to destroy other enemies.
Depending on how well you can catch up to the moving shell, you can get a lot of points by doing this.
Enemies will be lined up, ready to be annihilated, starting with three Goombas (the first one dead already)...
... and two more Troopas.
As you can see, you can get a lot of points by doing this, as the more enemies you defeat in a row, the more your total amount of points grows.
However, this level is also filled with little obstructions and pits to confuse, suprise, and shock you. If you're not careful, they can easily bounce shells back at you, or you can simply fall to your death.
This Q Block has a power up.
After each obstruction, it always starts again with a singular Troopa, or Paratroopa.
Here, you will have two Goombas...
... followed closely by more obstructions.
This top brick contains a star. This is extremely useful, as it allows you to go very far through the level without worrying about obstructions knocking back shells at you. The bottom brick has 10 coins.
You can either use the star, or the same strategy you've been using previously to get through this area of Paratroopas...
This brick is a red herring.
Just past it, though, is a Troopa...
...and still more Troopas.
Getting to the pipe means you're almost to the end.
However, not before you deal with a Troopa, Goombas...
...and more Goombas.
Take the stairs to the end.
Next is World 3-3.
Here, in World 3-3, we have the return of the official Athletic setting.
Tree top climbing and jumping make its return, with a slight twist seen later on. For now, it's best to deal with that Goomba by waiting for it to come to you.
This level features a lot more floating platforms than the previous one did.
They're not so bad, yet, but they will be eventually. For now, feel free to pick up the easy money.
Too more Troopas, more coins, and a Q block with a power up inside.
This jump can be rather obnoxious, and, unfortuantely, it is quite necessary to do in order to move forward. Getting a running jump will allow you to get up there with limited room for failure.
This platform will fall as soon as you touch it, so make sure that, if you do happen to land on it, that you jump away as soon as possible.
The top part is far easier than the bottom part, and gives you free coins while you're at it.
Here is where the level shows its true colors. As you can imagine, jumping on one side will lower it while raising the other side.
Try and stay on these platforms as little as you can, for they do not give you that much time to jump away and on to safer platforms. Those two platforms without support move horizontally, so wait until the perfect moment before you jump for them.
Also, that platform right there is quite skinny, so take care not to fall off due to poor traction when jumping for it.
It might not seem that way, but it is possible to make the jump to the other platform from where Mario is standing. Go as far away as possible, run, then jump, and Mario should just barely make it.
A couple more coins, but it's probably best to ignore the one on the bottom, unless you use that horizontally moving platform to get there.
That Paratroopa might seem like trouble, but it floats down low enough that it shouldn't be too much of an issue.
Once again, take care not to fall off these small platforms.
It would also be best to wait for the appropriate time before you jump on to this platform with the Troopas. In levels like this it is always best to play it safe.
Good news, you're almost there! Bad news, this is pretty tricky.
The tried and true methods of staying on these platforms for as little as possible is your best method for crossing this gap.
Getting a good score at the top of the flag is difficult, but possible. It requires staying on the left side of the balancing platforms a little longer than desired to get the right one up more. Jump from the right one, while running, and you should get a decent score. If you don't care about the score, then just play it safe, and jump down on to safe territory and get to the flag that way.
Thankfully, this world is done, and we can move on to the castle, World 3-4.
World 3-4 starts out pretty innocent so far.
Unfortunately, no sooner do I say that, but then we have this mess to deal with. Hesitation will get you killed in this situation, so wait for the first Podoboo to retreat then jump from platform to platform without stopping.
After that, you'll come upon some Q blocks, the middle one having a power up, while the others have coins.
There is a pit right after those blocks, and then three sets of two firebars. The first two, are not so bad, as they move in the same direction you are moving. Just wait for them to get out of the way, and move forward.
Unfortunately, the third set moves in the opposite direction.
The best way to go about this is to wait for the top bar to get out of the way, the bottom bar to point at around your feet or beneath you, and then jump through it as quick as possible.
If done right, you shouldn't even have to take a hit from it.
However, right after the fire bars, the fire balls start to harass you.
Since you also have to contend with Podoboos, wait for it to return back below before jumping across. Hopefully, the fire ball is also just passing you by as you prepare to jump.
Do the same for each of the pits. It is difficult, tedious, and takes lots of patience, but after this, it's all smooth sailing from there.
Plus, if you find yourself needing to calm down after that, here is a safety area for you.
After that, you'll start to see the platform with...
...Bowser, AGAIN! That pile of bricks right there can get pretty problematic, so jumping is probably not an option here.
In this case, your best bet is to run under him while he's in the air and hit the switch. Or, if you have a power up, you can simply take a hit and let your invisibility frames protect you.
Whatever you decide to do, hit the switch, and watch him fall in the lave for a third time.
Predictably, this is also not the right castle. Moving on, then, to World 4.