4 was gritty feeling. But good. The illustration style an backgrounds made the city feel hot. An at night cooler. Problem with this last riddle is if you don't know the rule how can you avoid cheating? Then again they are not playing but moving to their goal.
@takashichea: Color wise they use the fade an huge saturation for effects in this. Where as they just went overboard on Copellion. Cant remember exact quote from art teacher years ago but it was something like " tasteful is being restrained with style,while tacky is going overboard with it." Again thats just preference an opinion. But it kinda fits the restrained use of the huge saturation in this show.