This is pretty impressive! The attention to detail is amazing.
The toes do look a little funny, but it explains how he's able to grip the wall so well when he's wall-crawling.
Also, I'm always saying I'm a bit creeped out by the teeth in
pictures, but this is one picture where the teeth would have really fit the image. Without them, Green Goblin looks a bit like a man who's lost his dentures.
Overall, a really nice job on a cover reproduction! Thanks!