Industry watchers say, more than boys and girls, adults who refuse to grow up are being increasingly targeted by a toy industry promoting adolescence as a lifestyle choice.
Among the "Smart-Tech" toys at this week's Hong Kong Toys & Games Fair -- one of the largest of its kind in the world -- were smartphone-operated flying machines equipped with cameras and rotor blades that clearly had so-called "kidults" in mind -- particularly male ones.
"'Kidults' are not defined by age, they are defined by attitude," said Kenes Cheung, business development manager for Hong Kong-based manufacturer E-Supply International, which produces Wi-Fi and Bluetooth-enabled vehicles boasting infra-red and night vision for the likes of Toys "R" Us.
It was one of many firms illustrating how technological advances are helping push drone-like devices into the wired recreational mainstream.
"We're seeing a lot more products for the older player who has a smartphone," said Christopher Byrne, content director of timetoplaymag.com, a toy industry website.
"Guys especially have this inherent need to play, they never really grow out of it," he added, noting that girls tended to move away from traditional toys more quickly than boys but that cross-gender smartphone games such as Candy Crush were bringing more women back into gaming.
"Smart Tech" toys are an increasingly important segment for the industry, say economists, citing Asia's changing demographics where declining birthrates in places such as Japan and South Korea are pressuring producers to seek other markets -- such as grown men with disposable incomes.
"High spending power characterises these consumers," said Wenda Ma, an economist with the Hong Kong Trade Development Council, which hosted this week's Toys & Games Fair showcasing products from nearly 2,900 exhibitors from around the world.
Collectibles ranging from high quality action figures to replica assault rifles and cars were among the more adult-oriented items on display.
"A growing number of companies are introducing two lines for the same product, one for kids and the other for collectors," said Ma.
"Mattel has a strong collector business in Barbie dolls, Matchbox die-cast cars and the Hot Wheels racing system, in addition to the children's line of these toys."
The Hong Kong fair brings together a global array of buyers and manufacturers in an event that reinforces China's status as a production base for toy companies, despite rising labour costs and competition from the likes of Indonesia and Vietnam.
The popularity of smartphones and tablet computers has lead developers to make more toys that combine physical objects with apps or other devices.
"Whatever product it is, it must have this kind of technology built into it nowadays," said Yeung Chi-kong, a 51-year veteran of Hong's toy industry and vice chairman of Blue-Box Holdings which produces infant and preschool toys, electronics and collectibles.
"Toys are a cultural product that mirror lifestyle and changes in technology, and how parents want their kids to learn," said Yeung, noting the ongoing debate about whether tablet technology is a positive or negative tool for young children.
"Even a child's potty -- you have designers trying to build applications into them."
A recent survey by market research firm The NPD Group in the United States showed that 51 percent of children polled were using smart devices, with nearly 40 percent of those represented in the survey considered a primary user.
Augmented reality games generated buzz at the event, including a pink rabbit called TuTu that is powered by an iPhone app and developed by Hong Kong and Taipei based Roam & Wander.
Wilson Chiu, owner of Global Manufacturing Partners, which makes toys for Walmart and Toys "R" Us, has also developed augmented reality games, enabling children to use smartphones or tablets to interact with images on clothing or toys while keeping them firmly in the real world.
"Today there is a problem," he said. "Kids focus on devices without communicating with their parents, or with others," he said.
While some in the industry say children are more quickly ditching physical toys in favour of smartphones and tablets, tactile classics such as Lego remain popular.
British model railway maker Hornby, which has seen profits pressured by competition from tablets and app-based play in recent years, has updated its Scalextric car racing sets to reflect the influence of console and smartphone racing games such as EA Games' "Need for Speed", adding more elements to traditional head-to-head racing.
"There's still a big market for things that are hands-on, for something you can build yourself," said Philip Deery, international sales manager with Hornby.
"It's not all about this virtual world."