Needing a lead character for the game, Naughty Dog recruited American Exitus artists Charles Zembillas and Joe Pearson and met with them weekly to create the characters and environments of the game, eventually creating a character named "Willy the Wombat". The marketing director of Universal Interactive insisted that the character be named "Wez", "Wuzzles" or "Wizzy the Wombat". On creating the levels for the game, Zembillas and Pearson first sketched each environment, designing and creating additional individual elements later. They aimed for an organic, overgrown look to the game and worked to completely avoid straight lines and 90-degree corners. A Naughty Dog artist sketched every single background object in the game before it was modeled. The artists were tasked with making the best use of textures and reducing the amount of geometry. Dark and light elements were juxtaposed to create visual interest and separate geometry. The Naughty Dog artists would squint when sketching, texturing and playing the levels to make sure they could be played by light value alone. Correct use of color was an important goal for Naughty Dog's artists; for example, mutually accentuating colors were chosen as the theme for the "Lost City" and "Sunset Vista" levels. The interior of Doctor Neo Cortex's castle was designed to reflect Cortex's twisted mind.