Hardest Super Mario levels I've played

The Perfect Run - Super Mario Galaxy 2
Grandmaster Galaxy only opens up when you have collected all 120 Power Stars, and all 120 Green Stars! There ARE checkpoints, but contains four VERY HARD sections! If you're not 100% sure that you have SUPREME CONFIDENCE in your abilities, I would recommend coming into this level with at least 30 lives, just to be safe...

World 8-3 - Super Mario Bros.
This level is made out of nothing but massive pits, Bullet Bills, Koopas, and Hammer Bros.. All of that is already insanely hard, but imagine trying to pull all of this off with only a whopping 300 seconds on the timer, AND the fact that this is the longest level in the game! Timing your jumps is the key here to beating this level!

Tubular - Super Mario World
I've been stuck on this level for ages once, can't express how much I hated this level back then.

Luigi's Purple Coins - Super Mario Galaxy
After completing the game for the first time, a series of Purple Prankster Comets appear in almost every galaxy, giving the player the option to go through remixes of certain levels in the galaxy, forcing them to collect 100 Purple Coins. Sometimes under a time limit. This is the hardest of them all, because all 150 of the Purple Coins are on a giant eight-bit Luigi planet. The tricky part is once Mario lands on one of Luigi's sprites, it shrinks more and more until it disappears, forcing the player to collect two-thirds of the Purple Coins while only touching each sprite ONCE! >:^}

Secret Shine Challenge 14 - Super Mario Sunshine
The trip to this stage is hard enough. The actual stage is much worse. Mario has to hop on a pad while that pad is on a river, while trying to collect eight red coins. The catch is the river is poisonous and is an instant death.

Kamek's Revenge - Super Mario World 2: Yoshi's Island
The first part of the level, the player will have to avoid Kamek and his spells. The hard part is Kamek throws his staff wildly Baby Mario and Yoshi will have to reach a key, which will unlock the second part of the level. Once there, the duo will equip with skis, still trying to avoid Kamek.

Wing Mario Over The Rainbow - Super Mario 64
Why is it every hard level in Super Mario 64 seem to play the Athletic Theme, huh? Anyway, in this level, Mario must collect eight red coins in the clouds all throughout the level. The catch is the coins can only be grabbed by flying around the level using Mario's Wing Cap. Now, don't get me wrong, flying around with the Wing Cap is amazing, but in this level, flying leads to rage. If Mario isn't fast enough before the Wing Capand plummets into the sky below, he will land back outside Princess Peach's Castle near the moat, meaning the player will have to travel all the way back up to the top of the castle just to attempt to complete this ridiculous. Level again.

Lava Spire Daredevil Run - Super Mario Galaxy
This...was the hardest Power Star under the White Comet to get in this game without a doubt. Why? Well, because instead of being dropped off near the Sinking Lava Spire Planet or somewhere else close to the Power Star, you have to try to complete the ENTIRE LEVEL without taking damage or screwing up.

Champion Road - Super Mario 3D World
World Crown in Super Mario 3D World only opens if you've collected every single green star, stamp, and got to the top of the flagpole in every single level in the game. This is very similar to The Perfect Run except that there are no checkpoints! This level also contains six super difficult sections and yet, it's probably the longest level in the entire game! If you die, you HAVE to go back ALL THE WAY BACK to the beginning. Don't even expect to get it on your first try. If you did, then you're probably a wizard. Oh, and if you don't have a tanooki suit, you're pretty much dead.

Special 8-5 - Super Mario 3D Land
This is basically a rush level. Where it begins, you will only have 30 seconds to complete the level. There will also be a Cosmic Clone chasing you throughout the level. Trying to rush through the level is hard enough, but having someone dangerous chase you while doing it really takes the cake. Don't expect to get this on your first try.