Still room for improves.
The background is nice, but is unrelated to the sprite and a distraction. If you must have one, make it as plain as possible, maybe just a flat color with a hint of a cast shadow.
Good face and body, but the hand gesture is anatomically wrong: try it in the mirror! You can't make a thumbs up with vertical forearm.
The wheels are very, very plain (sweet irony, Mathias?), they are too dark, the spokes too white, they don't have shading / volume. And mostly they don't have a story: would it be possible to hint to how he came to get them, how they attach to his body, what he does with them?
yo thanks for pointing things out!
the hand is at an angle so it's not straight up sideview.. can still be improved though. uhm the background I was trying to go for something surreal looking because this guy is like an elf like dude (look at his pointy ears) in wonderland and the wheel is just like something from the cartoon that sticks out his body and works with no real logic behind it. Basically I was just playing around. hehehe
but I do agree that the wheels are too flat color wise!
I'll try and make it better, thank you very much Manupix!!!