Flushed and sweating, 31-year-old Annisa Enggracia Fidel runs back and forth to defend her fort from invaders -- hundreds of fellow adults all beating the blues by playing a nostalgic Indonesian children's game.
The tech professional is a member of Jakarta's "Playing Community", a group that gathers after work every Friday to let off steam in ways not usually associated with grown-ups.
Similar get-togethers have sprung up elsewhere in the Southeast Asian nation as larger numbers of burnt-out workers seek novel solutions for handling stress and maintaining mental health.
"The more energy we exert, the more we sweat, the more our stress is released," Annisa told AFP at the capital's main stadium, where about 500 people had come together.
"Of course, our happy chemicals are released too -- endorphins -- and that's what makes us feel more energized and motivated," she said after her game, which was enthusiastically cheered on from the sidelines.
Rapid urbanization has transformed Jakarta's metropolitan area -- now recognized as the world's biggest, with more than 42 million residents.
The expansion has brought faster-paced lifestyles, grinding traffic jams, regular flooding, severe air pollution and a dire shortage of public green spaces to unwind.
The Playing Community dates from 2024, when founder Akihiko Akira was battling work pressure and personal problems.
"It started because, like most Gen Z folks, I was stressed out by work, burnt out with life," he said.
The 24-year-old office worker found solace in "lompat karet" -- a game from infancy that involves jumping over a long rope made from braided elastic bands.
Videos he posted were met with a surge of interest from others wishing to join.
"The games make us reminisce about our childhood... not only can we be healthier, but we can also enjoy that nostalgic feeling with our inner child," Akira said.
That "can help release the stress inside of us, inside of our soul", he told AFP.
- Inner child revived -
The concept has since spread beyond Jakarta to other parts of Java island, such as Bandung and Yogyakarta, as well as to the tourist island of Bali.
Participants -- sometimes up to 1,000 per session -- are not charged a fee. They only need to bring their own water bottles and comfortable clothing.
Many activities are high-energy, including Annisa's beloved fort-guarding game -- known as "bentengan" -- and a variant of tag called "petak jongkok".
But some opt for less physically demanding escapism in the form of "congklak" -- a counting game using seeds or stones -- or "bola bekel", similar to jacks.
IT developer Imam Hidayat said he joined the Jakarta group after jogging past a Playing Community session last year.
"I was very stressed out because of deadlines, especially since I work in a corporate bank," said the 27-year-old.
"It makes me so happy. I played two games tonight, including 'bentengan' with many other people."
Initiatives like Playing Community are invaluable as a drug-free anti-depressant, said Jakarta-based psychologist Ratih Ibrahim.
"There's a sense of togetherness; you meet new people, and in that moment, you become human again," she told AFP.
Intan Permata, a 36-year-old homemaker and mother of three from neighboring Banten province, agreed.
"In our daily lives, we get so caught up in school issues, the kids, the house... It really feels like such a refreshing break," she told AFP.
"My inner child suddenly returned, all the sore muscles disappeared, and I feel happy. Very happy," said Intan.
