While I don't play with custom characters in SRB2 very much, I must say that it is VERY refreshing to see someone actually make a character from scratch.
That being said, I'll start my review.
Graphically, you did a pretty good job with this. Shading, drawing, all very nice. One problem that immediately arises is that the offsets on his running sprites are off. Notice how he seems to jump around.
http://i4.photobucket.com/albums/y119/SS2K5/FanGame-SRB2Stuffs/XWE.png
See where the two red circles are pointing? Mess around with those numbers until the running sprites are all aligned properly.
Another problem that arises is that the character is thokking. While this may not seem like a problem, when you consider the other options, thokking doesn't make too much sense. For example, wouldn't Gliding without climbing work better? It's not like you can't adjust the speed of the ability so that it works right. A faster glide that way might work better.
Running on water shouldn't be happening, quite simply, because it doesn't look right with the running sprites. It also has an awkward feel to it. May be best to just take that out.
And lastly, I understand why you'd use a spindash. But the ring trail just doesn't work. It may be best to just leave it as what it is normally. It's only really a good idea if it looks right with the character. And, if you leave it normal, SRB2JTE/ShufflARB2/PrettySRB2 will leave a nice image aftereffect with it, which would look a LOT better then a ring trail.