That is not true, Super Mario World is far more slippery than other styles. I know this for sure because i made an auto mario level and it wouldn't work anymore if i switched to a different style than Super Mario World.
Oh wow, I thought the Super Mario World physics in Super Mario Maker felt a bit more like New Super Mario Bros. U to me. I remembered that the physics of the actual SMW on the SNES was more slippery than those of the SMW style in SMM.
I further examined KingKyle's stages by downloading his stages to Coursebot as opposed to hit "Play", and my initial doubts are indeed real. I think it's easy to guess why "Super Bounce!" is a disappointingly boring stage that you'd regularly find in an Easy 100 Mario Challenge. Nothing much else to say here.
Beyond a Goomba being extremely close to Mario's starting point, it turns out that "Extreme" gets a lot of things wrong in the process too. A huge part of the stage's difficulty relies on cheap shots, and the rewards are disproportionately distributed based on how much effort it took the player to obtain them in first place, discouraging pure skills in favor of luck. I'll point out a few examples of where I found some of the bad level design in this stage.
1- Enemy hidden by the camera
In the high-jumping section with brick blocks and a few trampolines. Sounds safe, right? There's actually a green Koopa Troopa that'll eventually fall down while navigating this area. Since the camera don't let the player see this guy, he/she will most likely get hit because they couldn't see that from happening. That's not a challenge. That requires memorizing where the guy was, and therefore is one of those cheap shots.
2- Blind jump
Right after the hidden Koopa section, there is another bad level design thrown in because the creator thought it constitutes a challenge, yet relies on memorization instead. Again, the camera don't let player see what's below from this point and there's zero indication on where the player should be while doing a leap of faith. There are trampolines down below, but there's also a possibility of failing this one because the player would have enough time to react to land on one of them and falls down to bottomless pit instead.
3- Unrewarding reward placement
So, "Extreme" doesn't reward skills from the players. But what further exemplifies that issue are how illogically the rewards are placed. There's a secret that can be seen right at the start of level that players could effortlessly reach by jumping on the trampoline. Sounds neat, right? Well, that's one thing. But how they were rewarded is another thing.
For one, you were given a ridiculous amount of coins because of that very accessible secret? How about getting 25 coins by simply jumping in another easy to reach secret area, as shown above?
Also, if you managed to clear the hidden Koopa section and reach the right ledge far out of the camera, it'll lead you to a virtually non-existent challenge section, complete with a Fire Flower and a Star that won't be much use. Here's why:
If the player takes the upper path from there, which is easy to reach and impossible to die afterward, the player completes the stage.
The lower path is a a dead end without an appropriate redeeming reward whatsoever. Talk about disappointing, but hey, you can backtrack. But, getting back where they were is a bit trickier than it should be. Knowing on how bad is the timeframe for timing press on a trampoline, it's possible for the player to be forced to restart the whole level by accidentally destroying the brick blocks underneath the trampolines if the player isn't small Mario, never heard of an obscure trick that safely drop any item down and struggles on stacking trampolines.
When a player overcomes one of the most difficult sections of said level or find a difficult-to-reach secret, you should give them a proper reward to commemorate their efforts. The stuff they get should actually aid them to clear this stage easier or in a more interesting way than if they weren't rewarded.
Overall, "Extreme" seemed to be promising despite the cheap shot at the very beginning of the stage, but it ultimately fails to deliver the fun you were touting thanks to a number of questionable level design choices. Cheap damage/death sections due of unforeseen obstacles and unrewarding reward placement are what makes many players not bothering to give you a star. Also, if you were wondering why you couldn't place certain elements in a course, it's most likely because you filled the stage with tonnes of enemies, most of which didn't even needed to be there to begin with, which I noticed right away when I started analyzing this stage.
