Seven Wonders of the World, seven-star hotels and now, according to its creators at least, witness the arrival of 7-D cinema - complete with handheld guns, machine-created bubbles, and a few early glitches.

Shanghai Qing Yu Intelligent Systems Engineering claims to have come up with the concept and plans to commercialize it locally this fall.

The company is running a pilot version at the Shanghai International Science and Art Exhibition, which kicked off on Wednesday and runs until Monday.

The concept remains a little vague and may be just a clever marketing ploy - even the company's project director confessed to not knowing what one of the D's represented - but it more closely resembles a theme park attraction or multiple-user arcade game than a screening at your nearest multiplex.

In addition to 3-D specs, rotating seats and smoke machines, which have garnered lukewarm reaction as theaters worldwide experiment with films in 3-D and 4-D, 7-D has plastic ray guns and shoot-'em-up style arcade games.

"3-D is purely visual; 4-D is mostly about movement, that is, vibrating and rotating seats; 5-D is more sensual, such as thunder and lightning, water splashes and changes in temperature," said Ray Zhang, who works for the company. "There is no 6-D, actually. And 7-D refers to the interaction between man and machine."

Local media accounted for the lost dimension by referring to the interactivity between users on-screen, but it was unclear how this differs, if at all, from regular multiplayer games.

Meanwhile, the website of People's Daily reported on what sounded like similar 7-D cinemas opening in Beijing in March, and in Zhoukou city, Henan province, in July.

The latter features electronic guns and the simulated effect of wind, rain, thunder and snow "as though you are a character in the movie," it said.

"This is like the next evolution of computer games. It takes that as a basic foundation, but up to 50 people can (potentially) enjoy the experience at once. I feel that it's more like a movie than a game," Zhang said. "We can also tailor this attraction in different ways for different clients."

The company has invested 5 million yuan ($817,000) in the project and will open its first outlet to the public somewhere in the city's Jiading district in October, according to Zhang.

One 15-minute "movie" or ride will cost around 50 yuan per person. "If the market responds well, we'll expand."

At Shanghai Exhibition Center on Wednesday a long line had formed around a spacious black cube. Inside, six people bucked around on what looked like a borrowed roller coaster car in front of a large screen.

They were issued electronic glasses and video-game guns on the way in, asked to choose from one of three "movies" (10-minute computer game animations ranging from pirate attacks to air raids), and assigned characters. Afterwards, each was awarded a separate score.

The attraction opened at 9:30 am and within two hours only one of the six guns was still working due to damage done to the electronic cables.

"Come back tomorrow and have a go," said an exhibitor manning the exit door.

Shanghai local Mark Chen, 12, said the experience was "richer and more enjoyable" than playing on his Xbox, despite the technological hiccup, but still fell short of expectations. "The 3-D effects were okay, but the gun didn't work. It felt more cinematic than gamelike, because there wasn't enough interaction."