cavernous landscape, key item, dead cells game environment, rocky textures, dripping stalactites, bioluminescent fungi, moss-covered stones, ancient ruins, eerie atmosphere, dimly lit, torches on walls, subterranean river, reflective water surface, ambient occlusion, side-scrolling perspective, platforming elements, pixel art style, atmospheric shading, ambient soundtrack, action-adventure theme, hidden passages, treasure chests, skeletal remains, challenging platformer, 2D game art, atmospheric lighting, cavern exploration, game level design, detailed background, immersive experience.