

There's Mario, Luigi, Yoshi, Wario, Toad, and Peach. All of them are planned to be playable.
Mario is average in all stats, Luigi can jump higher but has less friction, Wario can deal damage to enemies when running (at full speed on the P-Meter) but has shorter jumps, Toad can run faster but has shorter jumps, and Peach runs slower but has her 'float' ability.
Yoshi is kind of a different case altogether;
He works as he did in Yoshi's Island, as in he can eat enemies, throw eggs, ground pound, and flutter jump.
However, he can flutter jump less frequently in than Yoshi's Island, (aka less times mid-air; you can't do it nearly indefinitely.) and he can only carry 3 eggs at a time.
Not only this, but he can only use 3 of the 9 power-ups.
Essentially, he's an "Easy Mode" character but cannot completely become overpowered.
Mario is average in all stats, Luigi can jump higher but has less friction, Wario can deal damage to enemies when running (at full speed on the P-Meter) but has shorter jumps, Toad can run faster but has shorter jumps, and Peach runs slower but has her 'float' ability.
Yoshi is kind of a different case altogether;
He works as he did in Yoshi's Island, as in he can eat enemies, throw eggs, ground pound, and flutter jump.
However, he can flutter jump less frequently in than Yoshi's Island, (aka less times mid-air; you can't do it nearly indefinitely.) and he can only carry 3 eggs at a time.
Not only this, but he can only use 3 of the 9 power-ups.
Essentially, he's an "Easy Mode" character but cannot completely become overpowered.
As I mentioned earlier, we currently have 9 power-ups.
3 are common, 3 are semirare, and 3 are rare in another sense.
The first 3 can easily be found in ? blocks across the game. They're also the ones that Yoshi's limited to.
There's Fire Flower we all know and love, of which I don't need to explain.
There's the new Battpack which stuns nearby enemies with electricity so that you can simply walk into them to defeat them. This has limited uses, but can be refilled by coins; the reason for limited uses (which should be around 8 at the start of the level) is that you can hold it down, and continuously run and shock enemies. The range that you shock enemies will decrease over that specific usage, but will reset upon the next use. Using the battery will only last about 2-3 seconds in total, as to not make this the most overpowered power-up.
It is strictly limited to 8 uses, so use them well.
The FLUDD power-up does as it does in SMS; spraw water. However, it doesn't transform like in Sunshine. The water does deal a lot of knock back to enemies, though, so it's good for those platforms that you don't want to jump on because there's an enemy in the way.
3 are common, 3 are semirare, and 3 are rare in another sense.
The first 3 can easily be found in ? blocks across the game. They're also the ones that Yoshi's limited to.
There's Fire Flower we all know and love, of which I don't need to explain.
There's the new Battpack which stuns nearby enemies with electricity so that you can simply walk into them to defeat them. This has limited uses, but can be refilled by coins; the reason for limited uses (which should be around 8 at the start of the level) is that you can hold it down, and continuously run and shock enemies. The range that you shock enemies will decrease over that specific usage, but will reset upon the next use. Using the battery will only last about 2-3 seconds in total, as to not make this the most overpowered power-up.
It is strictly limited to 8 uses, so use them well.
The FLUDD power-up does as it does in SMS; spraw water. However, it doesn't transform like in Sunshine. The water does deal a lot of knock back to enemies, though, so it's good for those platforms that you don't want to jump on because there's an enemy in the way.
The first couple dozen attempts at spriting, of which nearly none of them will really be this finalized.










Short-Term Items:















Enemies:







Blocks:

























Coins:






Background Objects:

Misc.:













The second few dozen attempts at spriting, in sheet form to make it look like I did more work
Well, most of them are in sheet form.
Veggies: 
Randomized expressions for each one you pull out to create some variety in the game.
Note to self: add in the last 2 new veggies
Scoresheet:
Thwomps:

Golden variation creates shockwaves, and the sheet to the right of it is the thwomp's effects that were pasted over it.
Revamped animation thanks to MM102.
Thwimps:
, and
, a golden variation that tries to land specifically on you.
Angry Sun:
Note to self: make angry moon
Phanto Masks:

There is no difference between the recolors, except for the nightmare version on the right which will chase you, even after dropping the key.
Because honestly, it's a lot more fun to go through SMB2 without dropping the key every few seconds.
SMW Disco Light Ball:

Hourglasses:

Because stopwatches are already planned to make a reappearance from SMB2, I can't use the same thing for items that add time to the game's timer.
Unfinished Shy Guy sheet:
The golden masks (on the right) were originally intended to be the shy guys that you could stand on, but now it's going to be white shy guys with colored masks.
Either that, or I'll give in and edit the Yoshi's Island DS sprites.
Yeah, I'll do that.
Anyways, snifit and blank Shy Guy masks are planned as well, as the blank masked-shy guys walk off of edges.
Also note the additional masks in the lower-right area; there's Anti Guy sprites, Phanto Guy sprites, and 2 alternate masks for the plain Shy Guy.
Anti Guys would only come in one color: black. They also chase you, and even jump 2 blocks high to reach the platform you're on.
Phanto Guys would summon a Phanto when they're picked up or defeated.
Unfinished for the time being because I didn't want to go back for the fourth time to redo/add to the sprites.
Roto Discs:
Square version since that's what my spritesheet came with.
Demo of the roto discs, since it's hard to tell what it'll look like.
Ninjis:
Bottom row is the walking animation, which is referencing the rather weird way that Ninjis walked in SMB2 due to limitations.
Note to self: Publish the recolored pink version that I've recolored since this image.
Hoopsters:

Yellow and green versions move faster when you intersect their vine, like in SMB2.
Trouters:
No difference between versions.
SMB3 bug:
Renhoek wanted this to be the horizontal version of the hoopsters.
It didn't work out, but at least there's a new animation for it.
Shells:
Shells... the iron/grey one sinks in water.
Cobrats:
Mystery Box:
From SM3DL/SM3DW.
Warp Box:
From SM3DL/SM3DW.
Bouncy Things:
Trampolines and things.
Cheep Cheeps:
I feel like there's a few frames of animation missing from here, but apparently not.
Or I could do the fish-out-of-water one.
And the vertical jumping that some fish do.
Dang it.
(Yellow one is from NSMBW)

Randomized expressions for each one you pull out to create some variety in the game.
Note to self: add in the last 2 new veggies
Scoresheet:

Thwomps:



Golden variation creates shockwaves, and the sheet to the right of it is the thwomp's effects that were pasted over it.
Revamped animation thanks to MM102.
Thwimps:


Angry Sun:

Note to self: make angry moon
Phanto Masks:



There is no difference between the recolors, except for the nightmare version on the right which will chase you, even after dropping the key.
Because honestly, it's a lot more fun to go through SMB2 without dropping the key every few seconds.
SMW Disco Light Ball:


Hourglasses:


Because stopwatches are already planned to make a reappearance from SMB2, I can't use the same thing for items that add time to the game's timer.
Unfinished Shy Guy sheet:

The golden masks (on the right) were originally intended to be the shy guys that you could stand on, but now it's going to be white shy guys with colored masks.
Either that, or I'll give in and edit the Yoshi's Island DS sprites.
Yeah, I'll do that.
Anyways, snifit and blank Shy Guy masks are planned as well, as the blank masked-shy guys walk off of edges.
Also note the additional masks in the lower-right area; there's Anti Guy sprites, Phanto Guy sprites, and 2 alternate masks for the plain Shy Guy.
Anti Guys would only come in one color: black. They also chase you, and even jump 2 blocks high to reach the platform you're on.
Phanto Guys would summon a Phanto when they're picked up or defeated.
Unfinished for the time being because I didn't want to go back for the fourth time to redo/add to the sprites.
Roto Discs:

Square version since that's what my spritesheet came with.
Demo of the roto discs, since it's hard to tell what it'll look like.
Ninjis:

Bottom row is the walking animation, which is referencing the rather weird way that Ninjis walked in SMB2 due to limitations.
Note to self: Publish the recolored pink version that I've recolored since this image.
Hoopsters:


Yellow and green versions move faster when you intersect their vine, like in SMB2.
Trouters:

No difference between versions.
SMB3 bug:

Renhoek wanted this to be the horizontal version of the hoopsters.
It didn't work out, but at least there's a new animation for it.
Shells:

Shells... the iron/grey one sinks in water.
Cobrats:

Mystery Box:

From SM3DL/SM3DW.
Warp Box:

From SM3DL/SM3DW.
Bouncy Things:

Trampolines and things.
Cheep Cheeps:

I feel like there's a few frames of animation missing from here, but apparently not.
Or I could do the fish-out-of-water one.
And the vertical jumping that some fish do.
Dang it.
(Yellow one is from NSMBW)
Imaginary Cake: 95% of everything (story, concept, sprites, etc)
alesan- coding
Victinistar- wasting my time concepts
Hans- cookie-related sprites mostly, as well as feedback on other sprites
MM102- pipe recolors and help with more sprites, as well as feedback
MM102 again- the awesome logo at the top of this post
Idiot9.0- undeserved praise
alesan- coding
Victinistar- wasting my time concepts
Hans- cookie-related sprites mostly, as well as feedback on other sprites
MM102- pipe recolors and help with more sprites, as well as feedback
MM102 again- the awesome logo at the top of this post
Idiot9.0- undeserved praise