@Roadconian
The magenta is transparency colour and the block is used for storing & cycling through mushroom, fire flower, feather & starman.

What it appears to be is a block with a dithering-based transparency effect.

@Roadconian It's a weird magenta block

i always that "THANK YOU!" seems a tad aggressive

I have no idea what the thing next to the 3up text is, but i'm assuming it's a placeholder sprite

@P-Tux: It's a checkboard platform which floats in water which appears to be unused because the only such platforms were wooden ones in Lemmy's Castle.

Where does the brown checkerboard platform to the left of the keyhole appear?

Ok, I've got them ripped and in the queue for an update to the Yoshi sheet, along with the egg's "THANK YOU!". The brown-recoloured gameplay egg turns out to be used in the after-castle cutscenes, but a different egg sprite is used for the credits and Baby Yoshis hatching cutscenes.

The egg on that sheet just looks like the gameplay one but given a recolour. I think that egg is the post-castle cutscene or THANK YOU! cutscene egg, while I'm talking about the eggs seen when the credits are rolling.

can't believe barack obama himself ripped super mario world sprites

The mentioned egg is on the Yoshi sheet.

Please add the credits Yoshi Egg here on on the Yoshi sheet. It's a bit darker than the usual one and uses the Mega Mole palette.

The 5up is actually used, but its sprite is vertically and horizontally flipped with the two 8x8 segments also being swapped:
https://www.youtube.com/watch?v=9T7qYJWQCL0
1:15

unused 5up texture

Fixed the empty block palette, also widened the mushroom head from Butter Bridge 1 since this is how it looks ingame.

I've read on The Cutting Room Floor that the Chain Chomp chain is a leftover from the Chain Chomp that was originally going to be in Super Mario World, but got it's graphics replaced by a different object.

+ Added note for chain & music note (both unused)
+ Ingame goal bar enlarged by 8x8 pixels
+ Added bounce sprite for note block, yellow and green !-block, yellow static rotating block with item in it
+ Erased foreground brick tile from Koopaling fight
+ Mirrored VRAM message block to match the one ingame, because for me, ingame variants are different in size, not if they're just flipped or anything
+ Added unused platforms
- ball bar stays on the sheet, in the end it's just five 8x8 balls moving up and down.

@P-Tux7 The message block is like that in the game's graphics bank for some reason. Maybe the properly flipped version could go in the Ingame section.

You might wanna mention that the chain and notes (grey row) are unused and hypothetical. I would also suggest adding the left/right bounce animation for the Vanilla Dome 3 ball bars and moving them to that sheet because it's only a few frames. The Goal Bar has an extra 8x8 extension in-game. This sheet forgets the bounce block shown when bouncing on a Note Block and the ground tile sprite used in Bowser's fight, and the unused giant leafy platform. Also, you got the Message Block backwards.

Nice work otherwise, especially with the boss fight backgrounds and the unused Yoshi sign. I would have never thought of those.