 To aid in the visual aspect of production, David Siller recruited Joe Pearson of Epoch Ink, who in turn recommended that Charles Zembillas of American Exitus be brought on board as well. Pearson and Zembillas would meet with Naughty Dog weekly to create the characters and environments of the game. Because the main character was Tasmanian, it was decided that the game would take place on a mysterious island where every possible type of environment could be found, with the added reasoning that an evil genius like Doctor Neo Cortex would require an island stronghold. On creating the levels for the game, Pearson first sketched each environment, designing and creating additional individual elements later. Pearson aimed for an organic, overgrown look to the game and worked to completely avoid straight lines and 90-degree corners. In January 1995, Rubin became concerned about the programmer-to-artist ratio and hired Bob Rafei and Taylor Kurosaki as additional artists. A Naughty Dog artist sketched every single background object in the game before it was modeled. Naughty Dog's 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 artists would squint when sketching, texturing, and playing the levels to make sure they could be played by light value alone. They ensured to use color correctly by choosing mutually accentuating colors as the theme for the "Lost City" and "Sunset Vista" levels. The interior of Cortex's castle was designed to reflect the inside of his mind.
