Art, as they say, is a personal thing. And the kind of person you are after six pots of coffee at three in the morning staring down the barrel of a deadline isn’t something you’d want anyone else to see. You’d probably bite someone. Give them rabies. The video game industry is full of bad box art created at that magical moment when the dawn is an hour away and the artist should have been unconscious long, long ago. Have a look at this gallery of box arts sins, would you? IGN has the story.
My favorite is when the artist doesn’t do the research. Not on some nitpicky detail, but things What Don’t Work That Way. See the magic bullet in the article for an example. If a bullet is flying around with its casing still on, better get a priest, son, because your ammo is possessed.