Shape

A shape is an enclosed space that is defined by its outline.

Naturalism

Naturalism in art is the way shapes, colors, and forms are depicted as they may be in nature. In this picture from Ni no Kuni, the forest scenery can clearly be seen in how it attempts to accurately portray nature. 

Pederson, Eric. "Ni No Kuni E3 2012 Demo Hands-On." ManaTank RSS. N.p., 15 June 2012. Web. 20 Feb. 2013.  http://manatank.com/2012/06/ni-no-kuni-e3-demo-hands-on/

Idealism

Idealism is the idea of perfection of beauty and form defined by society, an individual, or culture. Many role playing games, such as Guild Wars 2 featured below, give the player the option of customizing their own personal character. With this option, the player is able to create their own  ideal image, within the parameters that the game provides. 

Kain, Erik. "'Guild Wars 2' Review - Part 3: Six Things ArenaNet Gets Right - Or Very Nearly Right." Forbes. Forbes Magazine, 09 Sept. 2012. Web. 20 Feb. 2013. http://www.forbes.com/sites/erikkain/2012/09/09/guild-wars-2-review-part-3-six-things-arenanet-gets-right-or-very-nearly-right/

Curvilinear Shapes

Curvilinear shapes are forms that are made through the use of curves and flowing lines or contours. In the picture below from a dungeon in Tales of the Abyss, the whole structure of the platform as well as the interior platform are made of curved and flowing lines. 

Azizmb. "Tales of the Abyss 3DS Review." Game Crunch. N.p., 1 Mar. 2012. Web. 21 Feb. 2013. http://gamecrunch.co/2012/03/01/tales-of-the-abyss-3ds-review/