Okami was developed for the Sony Playstation 2 and later ported to the Nintendo Wii because the unique style of gameplay (specifically the celestial brush) and the motion controls of the Wiimote compliment each other perfectly.
The art style Okami employs is reminiscent of painting more than traditional cel shading, which ties in with the games premise of painting the world to interact with it. Both the promotional artwork and the in game graphics feature brush strokes heavily, including elements such as paper textures, watercolor and traditional Japanese calligraphy strokes.
This was not always the case however as early in the games development the art direction was more realistic with none of it’s current signature style, this photoreaslistic style was changed due to restrictions in the PS2 hardware and its lack of ability to render 3D environments.
Once the art direction was changed the studio started to compile different art styles that complimented the idea of nature and growth.
The styles that they chose and the game was subsequently inspired by were, Japanese watercolor and wood carving art of the Ukiyo-e style, though most notably the game borrows from the traditional Japanese art of Sumi-e, especially during the sequences involving the celestial brush.
The Celestial Brush is used when the player pauses the action and call up a canvas, which can be used to paint a series of symbols which effect the world, such as slashing enemies, building bridges and rejuvenating the landscape
The gameplay itself is a mix of action, platform, and puzzle gaming and has distinct similarities to The Legend of Zelda series, to which the games director Hideki Kamiya, a self-proclaimed Zelda-fan, has admitted.