A smartphone-controlled robot that fires foam bullets and a model of a tyrannosaurus with real bones are among the attractions drawing the crowds at Asia's largest toy show this week.

Aiming to shake off the global economic slowdown, about 2,000 exhibitors from 43 countries are displaying their wares at the Hong Kong Toys and Games Fair, the second largest in the world and now in its 38th year.

The 30 centimetre (one foot) plastic "iDroid" robot sports wraparound glasses that light up when controlled by smartphone systems via Bluetooth.

"The concept came about one day when we were thinking how to incorporate the latest technology with something fun for the kids," Eddie Yu, chief marketing officer of the robot's maker, Hong Kong-based Globalactive Technology Ltd, told AFP.

"Everyone has a smartphone these days, so naturally we thought it could be used to control a cool toy," he said, using his phone to make the robot perform Michael Jackson's Moonwalk to the delight of the young audience.

At other times it fires a toy machine gun at giggling toddlers, swivelling its mechanical arms.

Across the hall, Maja von Hohenzollern, a member of Germany's former royal family, was debuting her line of pink princess baby clothing, accessories and furniture.

Decked out in a sparkling bright pink dress suit, the blue-eyed blonde said: "Every girl deserves to feel like a princess -- a real princess."

"All the items here are based on the things I used as a child," she added.

The fair -- the second biggest after the Spielwarenmesse event in Nuremberg, Germany -- runs until Wednesday, and while it's all fun and games on the inside, manufacturers are having a tougher time outside.

The toy industry, which heavily relies on Chinese factories, has been hit hard by the sluggish US economy and eurozone debt crisis.

Hundreds of toy factories in China have shut down since the 2008 financial crisis. Rising labour and raw material costs in China have added to pressures on manufacturers.

Chinese company Shantou Qunsheng Toys used to have more than 5,000 factories in Guangdong province. The company, which makes cheap board games and plastic toys, said production plants are closing down one by one.

"Sales have dropped so much -- about 30-40 percent just last year," sales manager Maggie Chen told AFP. "Business just keeps going down. It's pretty bad."

"We need to find new markets, outside the US and Europe. Maybe we can find better opportunities in South Africa, South America, the Middle East or Russia."

For Philippe Rousseau, director of French-based company OID Magic, rising costs at mainland Chinese factories have cut profitability for his company.

"Rising wages and prices of product materials have affected us," he said.

Luckily some buyers still have cash to splash.

"People here are willing to spend," said local toymaker Calvin Lam. "We've been experiencing 10-20 percent growth in sales annually."

But not everyone is in a mood to play -- about a dozen demonstrators caused a stir on the first day of the show on Monday, protesting at what they described as a lack of improvement in working conditions at Chinese toy factories.

Waving a giant banner reading "Toy Un-Fair", the protesters accused major Chinese toy suppliers to US firms of violating labour rights.

"Excessive overtime hours, poor work safety standards and the lack of social insurance at these factories are only some of the things US companies are turning a blind eye to," protester Debbie Chan told AFP.