Marcus is a socially awkward, steroid-ridden bodybuilder who happens to be the biggest fan of the first Super Mario Bros.game...ever. His toilet seat lifts to reveal a Mario head. A picture of Shigeru Miyamoto, the inventor of the game, sits atop his TV. Now, clad in a Mario-printed outer and underwear, he ventures to a three-day social gathering of rabid Mario fanatics.

He dreams of finding long-lost brothers and sisters, of being able to talk to people who understand him. But forging life-long connections isn't easy at a gathering lorded over by a living yet pixelated King Mario who...