Fantastic Voyage - Environment Lighting - Feedback please

Above is my original concept art for my throat environment, the environment is now completely modeled and textures applied, (below) however I spoke to Jordan this morning and he suggested adding some lighting to my scene to add a little more depth, however we weren't sure if it was needed as the environment is supposed to look very 2D, and in my concept art it was very matte, however, I do quite like the "dark cave" almost effect created by the lighting (bottom image) and that it highlights the area where the action will be taking place. Feedback on whether to including lighting or not would be much appreciated, thank you.