I've just begun using Photoshop CS6 and I must say, I'm impressed with the quality of the software. I've only had it for 2 days but I can definitely see myself using it more often. Anyway, here are two cartoonish pieces of fan art that I've created to test the range of Photoshop. Let me know what you think! Criticism is always appreciated.

How long does it take you to make these?

I can't remember how long it took to complete the Super Meat Boy one. Maybe an hour or two. I didn't really have a set technique so I was just free drawing. Invader Zim took around 4 hours to finish.

Your coloring and shading is on point. Only thing I see that should be improved is the fire. It looks a bit...odd but other than that, the art is very good.

As a Diehard invader Zim fan, I would recommend slimming down his cheek bones and emphasizing his spleen.

That last part was a reference to a zim/dib joke.