National Video Games Day is celebrated Sept. 12, but with new technology and games, the ever-expanding gaming world may look different than you think.

"Games are getting harder, more complicated," said David Dodge, CEO of CodaKid, a school that teaches children programming for video games.

The video game industry made $91 billion in revenue in 2016.

And with new platforms like virtual reality and mobile, Dodge said the demographic playing video games has expanded.

"Video games used to be just for kids, and now no longer," Dodge said. "We’re seeing all kinds of adults playing games. Riding the subway in New York playing mobile games. Candy Crush was a huge hit in the past few years."

Because of the expanding demographic, Dodge said the industry is also very difficult to stereotype.

Gaming extends to nearly every age segment. The average age of someone who plays video games is 35. And 47 percent of gamers in the U.S. are female.

And platforms such as YouTube are thriving because of gaming. Millions tune in to YouTube for content on their favorite games.

But for every success like "Mario Kart", "Pokemon Go" and "World of Warcraft" keep in mind all of the video games that never made it big.

"There are thousands of games that get lost in cyber space that are very good games, but maybe didn’t get the right marketing or PR," Dodge said. "The idea was a little stale but it’s still fun, it’s just not as exciting. Maybe it didn’t have a good title."