A boy named Harley and his family attend a taping of The Banana Splits TV show, which is supposed to be a fun-filled birthday for young Harley and business as usual for Rebecca, the producer of the series. But things take an unexpected turn - and the body count quickly rises. Can Harley, his mom and their new pals safely escape?

When his car breaks down, a quiet loner agrees to clean an abandoned family fun center in exchange for repairs. He soon finds himself waging war against possessed animatronic mascots while trapped inside Willy's Wonderland.