Final answer:
The game criticized as "Sex in a Box" in 1966 was Twister, which gained popularity after being featured on "The Tonight Show" with celebrities Eva Gabor and Johnny Carson.
Step-by-step explanation:
The game that was criticized as "Sex in a Box" when it first released in 1966 and then became a hit after Eva Gabor played it with Johnny Carson on "The Tonight Show" that year was Twister. The game's physical nature, which involves players placing their hands and feet on a mat with colored circles, led to the controversial reception. However, the public appearance and endorsement by celebrities on a popular television show changed its image and contributed to its widespread popularity.