Nice... Shadow recolor.
Now as a former avid spriter, the genre is very fun and rewarding, especially when you get into actually creating animated sprites and work out how to make their motions fluid and such.
But... Well, I'm sorry to tell you this, but your edit needs serious work. First let's look at the actual technical end of things as far as the actual sprite. There's not really any shading to it, it's all flat. Plus there's alot of gray pixles which weren't colored in when you changed Shadow's color. In accordance to the Sonic Battle style of color, all that gray area needs to be made either a light red or a pink. As it is right now it looks poor and choppy.
Now onto the actual character design. It's... Well, it looks like Shadow after falling into a bucket of paint o_o; I highly reccomend you take a gander at
this because he explains it far better than I possibly could off the top of my head and provides visual references.