You may have been playing with toys since you were a toddler, but have you ever wanted to make one of your own? Two students from St Paul's Secondary School challenged themselves to build a toy, and learned a lot along the way.
Annabelle So Wing-ting, 15, and Cherry Yip Man-yee, 14, both Form Four students, won the Special Awards at My Toy Design Competition last term.
Annabelle likes strategic games while Cherry is more into track sets, and their winning piece is a combination of both: Space Escape, a toy inspired by and based on the solar system, using physics knowledge the pair taught themselves during the process.
The concept takes inspiration from popular games, from Monopoly to toy trains.
The theory behind their game isn't hard to understand: it uses copper wire, magnets and batteries to create an electromagnetic force that drives a little car through "space" following instructions on game cards.
The objective is to return to planet Earth, but "there is no win", says Annabelle. The girls designed Space Escape for teenagers of a similar age.
Making the game looked quite simple: it was just magnets and copper wires, they thought. It was only when they started trying to build it that they encountered obstacles.
For one, they were in Form Three when they started this project, and it was only a few months since they'd started studying physics at school. "We just started learning physics, but a lot of it is too abstract for us to understand. What's most important is what is learned while playing," Annabelle says.
"Neither of us is great at physics, but we learned a lot by searching on the internet," says Cherry, who would ask her older brother for help, while Annabelle would turn to her father. "Then the two of us would study and test the design together before we found satisfying solutions," she says.
"The level of physics needed for this project turned out to be beyond our expectation," Annabelle adds.
To gain an idea of the science involved, the pair watched a YouTube video of the "World's Simplest Electric Train", which applies the same theory and method.
They spent most of their Easter holiday designing the game, but outside of school they had to try to solve any problems without the help of their physics teacher.
The materials needed weren't too complicated; magnet, copper wire and dry cell batteries are easy to buy. But they had to be careful to get the right parts. They had to be bare copper wires, and the pair had to decide which diameter worked best.
The girls visited Sham Shui Po several times before they finally found one store that had the right kind of bare copper wires.
The competition committee assigned Annabelle and Cherry a tutor, who suggested they made the "planets" themselves using plastic capsule toys.
"It was good advice; it's DIY and more environmentally-friendly to reuse our old toys," says Annabelle.
Apart from that piece of advice, the girls were on their own. Winning the special award came as a big surprise.
"It was already an honour to be finalists, as the other finalists in the student group were university students studying design. They have more creative and professional ideas," says Annabelle.
Cherry recalled being presented the award on the day: "We were sitting there and discussing which design we think deserved the prizes and all of a sudden, our names were called. We didn't quite realise what had happened until 'age 15' was mentioned."
"The only finalists who were that young were us!" the girls laugh.
Now that they've had a try at toy designing, they've got a newfound respect for designers.
"It's not that easy, there are so many little things that require special arrangement or improvement, especially when there are safety issues involved," says Cherry.
But that hasn't discouraged them. Annabelle says: "When I grow up, I would love to take on toy design for real."