What I can say about this character so far is that he seems pretty shadeless. You really should try giving him some brightening and a bit more of detailing around the outlines. I also think he's way too small. From what I remember, he was around Tails' size, if not a little bit smaller.
Also, your Tails Doll feels a bit too out of character. I say this because of the fact that he can actually use his tails and actually walks instead of just floating. The problem with having him to fly is that it makes him exactly like Tails, gameplay wise. As for the walking, he's really mostly known for floating when moving around, and I can hardly imagine that he can use his feet to begin with. If you try to recreate the way he "walks" in Sonic R, then the character would already be more unique and distinct in here.
Another thing that's been bothering me is his eyes. You got the shape pretty much correct, but the problem in here is his pupils. Looking at this reference picture, you can tell that they're always pretty much centered:
Not to mention that the ears in your sprites pretty much feel a bit too small, and the gem seems to be a little too low. You should lift up that gem a bit, at least in most of the animations. This is also just a suggestion, but you might want to add stitches to his body, but not way too big ones. One last thing would be that you forgot to give him his little fringe hair.
That's all I wanted to say. Keep in mind that while there's a lot to fix, this is pretty much my favorite attempt at a SRB2 Tails Doll I've seen. This is mostly because that, so far, this Tails Doll's appearance is the closest to the Sonic R design, and just feels really accurate, compared to the other full character attempts I had seen before. Your version and MonsterIestyn's sprite are my favorite ones so far. Shame that he had only made a single sprite, and it's very old even:
If it's of any help, you could use his sprite as a reference. Except for his face, hands and legs, as those seem very oddly pixelated. If I get some time later on, I could help you on getting a good sprite design for your Tails Doll, but just one sprite.
Also, your Tails Doll feels a bit too out of character. I say this because of the fact that he can actually use his tails and actually walks instead of just floating. The problem with having him to fly is that it makes him exactly like Tails, gameplay wise. As for the walking, he's really mostly known for floating when moving around, and I can hardly imagine that he can use his feet to begin with. If you try to recreate the way he "walks" in Sonic R, then the character would already be more unique and distinct in here.
Another thing that's been bothering me is his eyes. You got the shape pretty much correct, but the problem in here is his pupils. Looking at this reference picture, you can tell that they're always pretty much centered:
Not to mention that the ears in your sprites pretty much feel a bit too small, and the gem seems to be a little too low. You should lift up that gem a bit, at least in most of the animations. This is also just a suggestion, but you might want to add stitches to his body, but not way too big ones. One last thing would be that you forgot to give him his little fringe hair.
That's all I wanted to say. Keep in mind that while there's a lot to fix, this is pretty much my favorite attempt at a SRB2 Tails Doll I've seen. This is mostly because that, so far, this Tails Doll's appearance is the closest to the Sonic R design, and just feels really accurate, compared to the other full character attempts I had seen before. Your version and MonsterIestyn's sprite are my favorite ones so far. Shame that he had only made a single sprite, and it's very old even:
If it's of any help, you could use his sprite as a reference. Except for his face, hands and legs, as those seem very oddly pixelated. If I get some time later on, I could help you on getting a good sprite design for your Tails Doll, but just one sprite.