In the second overworld, some of the path tiles behind the destroyed castle look weird.
In
Go Fast, Don't Run, there's some cutoff here. It can be found elsewhere in the stage as well.
In
Soup of Star, there's a strange palette here, and it can be found in other places too.
In
Smorgesfall, some corner tiles have cutoff, and in the case of the second picture, there's a bush tile that looks misplaced as well.
In
Work Hard Jump Hard, there's cutoff at this rope. Strangely enough, there's only cutoff on the right side of the block.
In
Carpainter's Palace, if you miss the ON/OFF blocks at the end (which you'll only be able to do on purpose, but still) you'll be softlocked.
In
smw-dustbowl-v2, there's some cutoffs all three images, and the Bullet Bills themselves are bluer than usual. The latter might be intended though.
In
Blighted Beach, there's some cutoff.
In
Big Boo House, the hud goes behind the foreground at times, and during the boss battle, one of the Boo Circles moves much faster when you return to the boss with the key.
In
Aerostazs, there's minor cutoff
In
GhostP.E.A.R, there's some cutoff, and the name should probably have a period after the R as well.
In
Sky Landfill, there's some cutoff.
In
Replica Prototype, there's some cutoff
In
Ocean of Nonsense, there's some cutoff.
In
In 100 Percent Joj, there's major cutoff beyond the goal. I assume that part of the wall goes slightly beyond a screen, which causes the auto scroll to (presumably) go further than intended as well.
In
D-Runnin, there's some cutoff, as well as a giant pipe that, just like the one found in
Super Yoshi's Island has one white line too much. Also, if the intention is to make it look like the two halves are one single pipe that's split in half, then the white line on the Right half shouldn't be there either.
As a side note, I really like the troll move right before the goal xD.
In
Rise, there's some cutoff.
There're no auto-move after you finish
Phase Three and
Blackwater Current.
Another note about
Blackwater Current is that's it's the one and only stage where I found the difficulty to be more annoying than fun, which is because of the floating platforms in the insta-kill water.
Some of the platforms have two of them stacked on top of each other, while some don't. I get that this is done in order to make some of platforms safe to stand on, while some of them will sink into the rising/sinking water.
This isn't a problem in terms of level design, but what is a problem is that there's no way to tell the difference between the two variants until you land on them (I think), so almost every death I experienced in the stage was me jumping onto a platform with the assumption that it won't sink, panic jumping once I realize that it will sink, and that panic jump then pushing the platform deep enough to cause an insta-kill.
I have no idea if there's any way to improve this, but this was the only stage in the game where I didn't enjoy the difficulty.
In
Bowser's Castle, there's some cutoff. I won't comment on cutoff beyond this point since it's pretty obvious that the cutoff in the final two worlds is intentional.
In
Looping Jane, this strange door appears near the midway point once you reach the final room. I assume the intention is that it's a shortcut to the final room (like in another few stages), but you can't enter this one.
In
First Wonder, if you go too far ofscreen in this area, which is quite easy, the spiny will despawn, with no efficient way to make it respawn, creating a somewhat softlock.
I also have two final notes:
Is Mario meant to have some greyness in his colour palette on the second to last overworld and in
Phase Four? It might be intentional, but these two being the only instances makes me think it's not.
Are the No Yoshi sequences at the beginning of
Second Wonder and
Third Wonder meant to be there? It could be that they're meant to be part of the mind-f**kery that's going on in the final two worlds, but in my case, the cheerful music broke the immersion.