Really the first thing I noticed going into Coppelion was the fact that all three of the girls were either extremely plain, or that is the normal color of skin for humans in this anime. Well, it didn't take long to find out these girls are actually genetically modified to withstand these harshly radiated lands -- and they are called Coppelion, hence the name of the anime.
As far as the art style, there seems to be a trend in anime where characters have extremely prominent outlines -- almost to the point of each character looking like they are popping out from the background. Shingeki no Kyojin did this to some extent, but Coppelion is far more noticeable because of the characters looking so pale. It isn't that bad, but just something I've noticed from time to time.
Story wise, this first episode has potential to be something very interesting. However, the fact that this episode was mainly just setting up all the detail, there wasn't much there to hold my attention. I do hope it gets better in the next few episodes, but the best I can say about Coppelion is that it shows potential.