A game graphics, one of computer graphics, has grown rapidly and diversified expression techniques through continuous trials and studies. Rendering methods in game graphics are divided into two branches. The one is Protorealistic rendering method expressing realistic images like photos and the other is NPR(Non-Protorealistic rendering) method expressing emotion and artistry of human being. This paper analyzes how NPR techniques are used in game and what features are in their applications. And this paper suggests various effects for game graphics in an artistic viewpoint. So, this study aims at supporting production of more emotional, familiar and artistic games by understanding merits, demerits and applicabilities of recent NPR researches.