@bombodombo yea the fully black color is too much

overlay the outline

This isn't NES accurate, one too many colors per sprite and the color palette isn't correct

The references are reversed

YorkieYT: The Sonic sprites can be found here.

Will the Sonic Sprite be released?

not bad

AleGamer700 - how did you remove the white cover in the thumbnail?

I´m waiting what my update was accepted

Sorry for don´t answer.
1) Sorry for the stolen pixel art form Sonic 1 Megamix. I was to correct that.
2) Sorry for the error in the parody of Sonic Adventure 2. I NEVER played Sonic Adventure 2. Why? I´m poor. Like to much people from Latin America. (#SaquenmeDeLatinoAmerica)
3) If i don´t speak so good english, that because I´m Spanish-Speaker

Looks like the art style is from that NES rom hack.

@Greenknight9000 - That's the same problem with my first sprite sheet, I honestly can't even figure out how to remove the white cover in the thumbnail. I got really scared if I was in trouble for not making a sprite sheet correctly but than i just got over it because this is just a website. so in all things about this sprite sheet as i wished I and AleGamer700 (Or anyone that is new here) can possibly improve our sprites customs in a meantime.

And it also seems like the Shadow pixel art is a recolored version of Shadow's ending sprite from Sonic the Hedgehog Megamix.

@KostyaGame the bruh I also noticed that it was from (what I see) an outdated version of a Shadow in Sonic 1 hack! If anything, I feel like AsuharaMoon's Shadow hack would've been better suited (with permission given, of course) and on top of that, the sprites are clearly edited versions of the sprites used in the Sonic the Hedgehog NES Improvement Hack, which I see no credit for.

Speaking of sprites, I know this may sound harsh, but I still find it pretty lazy that the "running" sprites are just four frames of the walking sprites with just minor edits, actually, this applies for many of the sprites here; there's actually a ton of sprites that's more-or-less just straight-up Sonic! You didn't even change the quills in quite a few animations there, like "Waiting", for examples - you even forgot to change the sneakers in the lying down sprites.

As this is your first spritesheet, I'll give the benefit of the doubt and say that you're new to spriting, so using a pre-existing base to work off of is understandable! I see good potential in you and this sheet. Look at sources of inspiration, like the previously mentioned Shadow in Sonic hack for example and see how you can add your own spin to things with these sprites, if that makes sense; you've actually already done this with the crouching sprite, so I say you've got it in you to really turn this sheet around!

Yeah I was gonna say what KostyaGame said, u should give credit to the guy who made that pixel art, and plus u got the lines swapped in that sa2 skit down there

why you steal Shadow's Pixel art from STH1 ROM hack??

This was certainly unexpected, nice job!