As he and his brother watched the wind blow the puzzle-like constructions along the ground, the toys ultimately would be carried off into the desert near Kabul's main airport where the boys were not allowed to walk -- a restricted area littered with land mines and unexploded ordnance.
Hassani and his family left Afghanistan in 1993 after his father was killed. But as a design-school student in Eindhoven, Netherlands years later, Hassani's childhood memories from Kabul became the inspiration for an invention he hopes will save lives back in Afghanistan. It is a wind-driven mine-clearing device that Hassani calls a "Mine Kafon."
"It actually began a very long time ago when I was a kid. We used to play with these kind of objects where there were a lot of land mines. We grew up in an area like that," Hassani says.
(WATCH: The Mine Kafon in action)
"Then when I was at [design school] and I tried to do a project for graduation, I was trying to think about the past and come up with new ideas. I put these two ideas together and Mine Kafon was born."
The Mine Kafon -- which in Dari means "Mine Exploder" -- is about the height of a man. It has only been built as a prototype so far. But Hassani and an explosive ordnance disposal team from the Dutch military have taken it to Morocco for desert testing. Hassani now is trying to attract funding to set up an organization that can deploy more test models in Africa and Afghanistan.
At less than $60, the Mine Kafon's price tag is a fraction of that of high-tech mine-clearing robots with sophisticated detection sensors.
The human-driven Aardvark mine-flailing vehicles used by NATO to clear Bagram Air Field's massive compound north of Kabul cost about $500,000 each.
With more than 10 million land mines still awaiting removal in Afghanistan, Hassani says his device can be useful for villagers who might otherwise have to wait decades for their farmland to be cleared.
"Mine Kafon is actually a wind-powered anti-land-mine ball. It has a core and a lot of bamboo poles integrated in it. Every bamboo pole ends with a disc. It looks like a dandelion seed," Hassani says.
"So it moves around in the desert and if it hits a land mine there will be an explosion because the Mine Kafon is as heavy as a person and it mimics the feet of a human being. In this case, it destroys itself in the place of a human."
Hassani also attaches a GPS tracking device within the core of each Mine Kafon. That allows its location to be tracked and mapped in real time on the Internet. He says each device can detonate up to four land mines before it is destroyed.
Mine-clearance experts say there are some drawbacks to Hassani's invention. Since it is moved by the wind, a Mine Kafon creates random footpath-sized swathes through a field. It needs a push in a strong wind to move.
By comparison, a mine-flailing vehicle like the Aardvark is used to systematically clear an entire field by beating three-meter-wide strips of ground with chains that rotate 300 times each minute. Every piece of ground is struck at least twice, with the chains digging down 20 centimeters.
Even then, flail vehicles do not have the 100-percent efficiency needed to declare a field safe for farming. But they clear out vegetation, making it easier and faster for human teams to check an area manually.
Hassani admits there are limitations to his invention, but he sees his device as a way for local villagers to cheaply survey areas they know are dangerous.
"For the big [demining] companies, it would be totally a different way of clearing land mines because they are used to doing it the same way for 60 years now. For them, it will be a big challenge to accept this idea," Hassani said.
"But on the other hand, it is very cheap. It is very affordable. So that could be also a [benefit]. And it can even help villagers if they are provided with these bamboo poles and these puzzle pieces. Then they can construct them and put them in locations where it is dangerous."
After getting feedback about his prototype from experts, Hassani says he has begun designing a cylindrical Mine Kafon that could clear wider paths.