I would have guessed that this game was made by Hothead games, makers of the Penny Arcade games, based on the art style. I am 96% certain that the nose for MC Gutterpants is the exact nose that I chose for my custom PA game character. Is it common for art assets like these to be recycled in this way? This is the first time that I can think of it.

Once you have an art style it's kind of hard to detour from that style on minor things that is what gives it the look. It give it the style if you mess with the small stuff to much then of course it becomes a different art style.