New Super Mario Bros.: 7-1

World 7 is a cloud world. In this level, we'll find platforms on paths. Take the first platform to the right, then transfer to the higher platform. The platform will fall off its track and drop to the lower one so you can get the 1st Star Coin. It will go to the end of the line at the left and go back right, then fall into the void. Jump to the clouds to before it falls off. Here, you'll need to move quickly to get on the flying item block. Get on it before you reach the winding path of the platforms and don't hit it. It will take you over the void to a pipe. The pipe takes you to an area where you'll find lots of coins and ropes on gears. The ropes on gears will take you to the 2nd Star Coin and a green pipe back to the main level. There are more platforms on paths, but this time you'll have to contend with a respawning Fire Chomp. Fire Chomps have a tail of fire which represents how many flames they can shoot at you. If you don't stomp it before the tail runs out, it will explode. There are Red Coins in the area. Transfer to another platform which takes you to the pipe to the flag. To reach the 3rd Star Coin, take the platforms instead of taking a ride on the flying item block. Go up the pipe at the end of the path, then take the higher path to the 3rd Star Coin.

Super Mario 3D Land: 7-1

We start off on dry land and can see the goal across a river. The flagpole is fenced in, so we can't just jump over the river. The green pipe on our side is fake, but breaking it reveals coins that lead the coins over the water. We jump in and sink to the bottom. There are Cheep-Cheep swimming around. We go right, then double back to the left. Behind the six crates is the first Star Coin. Hitting the P-Switch lowers a rock, allowing us to progress. We pass two Porcu-Puffers to a green pipe. The room has lots of coins. We swim up after leaving the green pipe and reach the midpoint. Instead of moving forward, we find the third Star Coin by diving down past the three eels, moving to the right, swimming up, and finding it in a tunnel. The area has a current. We swim up to a green pipe to the flagpole.
Take 2- We take the same path to the third Star Coin and find the second Star Coin in an alcove over the tail of the lowest eel. Wait until the eel swims forwards, then swim behind it, then up. The alcove is between two eels, so swim carefully. We reach the flagpole.

New Super Mario Bros. Wii: 7-1 -- To the Underwhere!

This level starts off with a rock platform that Mario cannot climb. If Mario runs into the platform, he'll find ledges to climb, as well as a few coins. After going through the pipe, there are tilting and rotating platforms that move at different speeds. I got a 100-coin 1-up (thankfully, because I only had one life left). I got a Super Shroom and lost it to a Piranha Plant, but power up at the midgate. I skip the 1st Star Coin and went down a yellow pipe. I got a Helishroom and the 2nd Star Coin, but fell into the void.

Take 2- I died from a Piranha Plant and get another Game Over, for 14 continues, 3 of which are not from multiplayer.

Take 3- I got a Super Shroom and lost it to a Piranha Plant. I reached the midgate and powered up. I skip the first 2 Star Coins, and get a Helishroom. I can spin to get rid of some of the fog in the level. I get the 3rd Star Coin and a 1-up at the goal.