A Sonic fan huh?
Also, I would probably specify what such trade would consist of. Like, what pixel art you can exactly offer? Are there any limitations in what you can and cannot draw? It's pretty vague and considering that while you did send some examples of what you can draw, you don't have to draw anything close to that and still fulfill the agreement. Like you only specify it to be exactly one pixel art, which could be even something as simple as drawing a box or something as complex as rich landscape. Adding a bit of clarity could help a lot.
