With its oozing, slimy appearance, it might not look very appealing.
But the demand for gunge has never been greater and now, one Hull entrepreneur is seeking to build a business out of it.
Leigh Sumpter's company Phalanx Entertainments offers laser shoot-outs alongside goo.
He believes both have an appeal for adults and children.
"Gunge has the humiliation factor and it's fantastic for raising money for charity," he said.
"Laser tag is a lot of fun for the kids – paintball is quite painful, but a lot of parents will let their kids play laser tag.
"There's always a perception certain ages can't play laser tag, but we've had all ages, from four to 95."
Based at 16th Avenue in north Hull, Phalanx offers mobile laser tag using Quasar guns in a 1,500sq ft moveable arena.
It offers less steady business than a fixed site such as those operated by major rival Laser Quest, but the advantage is the freedom to travel.
"We go absolutely anywhere. We don't hire out much in Hull because people don't know what it is, but we do events across the country,"," Mr Sumpter said.
"We do fairs, charity events, even birthday parties – we've got a birthday party coming up in Hull."
Mr Sumpter suffers from cerebral palsy and genetic disorder Marfan syndrome, which poses an extra challenge in a labour-intensive industry.
But he is determined to succeed.
"I wanted to prove a disabled person could do stuff," he said.
The entrepreneur's dream is to open his own fixed site in the city.
However, at a cost of some £200,000, that remains a way off.
With guns alone costing about £2,000 each, it takes a lot of cash to set any sort of business up.
At present, the owner is aiming to turn over about £17,000 a year. But he is keen to carry on growing.
"A moveable arena was a step in the direction of getting into the world of laser tag," Mr Sumpter said.
"My aim is to get the money in and go static, but I don't foresee that happening soon. I need to make people aware of what we're offering."
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