With virtual reality all the rage at CES this year, Virtuix is hosting the first-ever eSports tournament in VR. The company connected four HTC htc Vive headsets to four of its Omni multidirectional treadmills, allowing players to pick up a replica gun and run through a virtual arena in a competitive multiplayer first-person shooter game called Omni Arena.

Jan Goetgeluk, CEO of Virtuix, says his treadmill puts the “sports” into eSports.

“Now players will need to be physically fit and trained in addition to being a strong gamer,” Goetgeluk says. “We feel that bringing eSports and VR gaming out of the chair and adding an active physical component creates an extra layer of excitement for both competitors and spectators. The faster you run on the Omni, the faster you will move in the game.”

In the first two days of CES, over 100 players engaged in 30-minute gameplay sessions. Virtuix offered two one vs. one gaming sessions, allowing more people to get into the game. The custom-made video game supports additional players in the arena.

“To have an active VR experience like a first-person shooter, you need an Omni,” Goetgeluk says. “First-person shooters are very hard to play in VR with just a head-mounted display on while seated or standing due to safety issues, space constraints, and simulator sickness.”

Goetgeluk says Virtuix will explore how it can work with established eSports leagues like ESL, Major League Gaming, and ESWC. This is just the first step into virtual eSports, and he says the CES demonstration can be replicated anywhere.

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Virtuix has raised over $8.3 million since April 2014, including a recent round that included funding from billionaire Mark Cuban. The Omni was pitched on “Shark Tank” a few years ago, but all of the sharks passed on the technology. Then Cuban changed his mind last year.

“We have a great relationship with Mark Cuban and our other investors,” Goetgeluk says. “Our investors are excited about virtual reality and the important role we play in this emerging space as the leader of the active VR category.”

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During CES, Goetgeluk says Virtuix is conducting a “testing-the-waters” campaign on SeedInvest under the new mini-IPO rules of Regulation A of the JOBS Act, which allow the general public for the first time to potentially invest in tech startups.

“Each week we receive requests from supporters who want to invest in Virtuix, and now with Regulation A, our customers and supporters may have a chance to buy shares in Virtuix alongside Silicon Valley venture capitalists and global institutional investors,” Goetgeluk says. “We received more than $5 million in investment interest from the public in just the first 48 hours at our page.”

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Virtuix began shipping Omni units to customers last month. Goetgeluk says in the next few months the company will ramp up production to work through the backlog of close to 5,000 orders.

The Virtuix Omni is platform-agnostic and also works with Facebook’s fb Oculus Rift. In the future, the device will work with Sony’s sne PlayStation VR system.