Porygon: Not bad for a first try. I don't know what the original image looked like, but it doesn't seem like a lot has been done other than some filters. The size is uneven and I think it looks somewhat plain.
I'd resize it so it's square, give it nice background, and maybe some lightly applied textures to make it more dynamic. I think it's also best to not have text, but that's just a personal preference. (Since you said you're new with Photoshop, I'd say start practicing with the Lasso tool to crop images -- it makes things so much easier!)
Helvecta: Wow, wow, wow! Very nice work. I love your colouring -- I can't wait to see this finished. I'm something of a rookie at vectoring, especially on such a large scale, but I think you're doing an awesome job. <3