The key to capturing something as challenging as chronic kidney disease was to create a visual tone comparably unsettling. To achieve this, Dan and Jason made the background environments stormy and gritty. The characters were given complementarily dark designs. Uric acid became a jagged, spiky monster who'd be every balloon's (not to mention kidney's) worst nightmare. And the afflicted organs and appendages—kidney, heart, bone, foot, and hand—were each given anthropomorphized faces and limbs that brought their deteriorating downfalls into stark, painful reality.