I LOVE the dynamic angle here! The curved road is such an awesome perspective, and it adds so much depth to the piece! Sonic is full of action in this piece; his facial expression is conveyed very well, and the curved shoe is very slick. I love how you made Eggman's eyes and teeth kind of glow; it reminds me of the silhouette Eggman moments from the comics.
How long did the shading take you? Because it really paid off! The city's lights are so beautiful, and I love the gradient on the road. The smoke from where the laser hit the road is also a great touch. Everything about this piece is just perfect... How did you do it?! I must know your secrets!!! AAAAAHHH!!!!!
Seriously though, great job all around. I would rate this 6/5 stars if I could.