Dominic Carroll’s bedroom resembles a sophisticated office with a black leather couch, finance books and a curved monitor and computer with a transparent window. 

Carroll is the creator of a popular video game called "A Very Hungry Pikachu." He designed the game on Roblox in 2015 as a joke, but then it blew up. On Monday, live stats showed 243 active players in the game. In that hour, he made $9.43.

"I was really young and messing around with the code and platform," the 15-year-old Waterloo sophomore said in his office next to a name plate that says Owner and CEO Dominical Inc. "A couple years later, I added things to buy because I noticed that a lot of people were joining. I remember when it hit 100,000 plays."

Now it’s at 19 million. Carroll designs and pays for advertisements to find new players, who are in the 8- to 10-year-old age demographic, he said. Players can buy points and premium tools to take down Pikachu, such as a gun, which costs $12.50 and has been purchased more than 5,000 times, or a $2.20 rocket launcher that 18,000 kids have bought.

"It was a dollar. I recently raised the price."

Carroll joined Roblox, a massive multiplayer online game creation platform, as a gamer in 2011.

"I was actually spending money on stupid things like this," he said. "I was one of these kids."

Then he found out he could design his own game and make money doing it. His programming screen features thousands of lines of code that he typed.

"There’s a lot of games made typically by college students," Carroll said. "There’s students who have paid their tuition with this."

In 2017, Carroll created a new game and learned a valuable lesson: simplicity is key when appealing to a young audience.

"This game has tons of features and only 124,000 visits," he said. "I lost money and two months of my time. That’s the risk you have to take when you start a new project. You don’t know if it’s going to be popular. It had too many features."

"A Very Hungry Pikachu" has a simple design and objective. 

"A large creature is running around destroying the city you’re in and eating the players," Carroll said. "The characters are simple and goofy."

Kids spend an average of 10 to 15 minutes playing the game. In the beginning of 2017, a popular YouTuber with millions of followers made a video of himself playing Carroll’s game. 

"He just found the game and started playing it. He actually spent money on it," he said. "It just blew up. I received a pretty big check that month."

Carroll bought everything in his bedroom besides a computer monitor that was gifted to him. He’s invested most of his money in stocks and is currently reading "Fire Your Stock Analyst" as well as other finance and programming books.

"My two main focuses right now are finance and programming," Carroll said. "The idea is that I’m going to get really good at this really early."

Carroll explained rubber duck debugging and the story of a programmer who bought a rubber duck to talk to about his code and he figures out the problem. Carroll got his own rubber duck and now has a collection on his book shelves. Carroll wants to develop software for websites and companies in the future and eventually own his own company.

Reporter Kelly Maile can be reached at 330-541-9416, or @KellyJMaile.