Jarindr Thitadilaka says he made as much as $2,000 a month last year from his collection of digital pets, which he would breed and send into battle to win cryptocurrencies.
The 28-year-old from Bangkok was playing Axie Infinity, one of a new breed of blockchain-based online games, dubbed "play-to-earn", which blend entertainment with financial speculation.
These games can make for lucrative businesses amid the hype around NFTs and virtual worlds, attracting millions of players plus billions of dollars from investors who see the games as a way to introduce more people to cryptocurrency.
In Axie Infinity, users buy virtual blob-like creatures with varying attributes as NFTs, or non-fungible tokens - digital assets whose owner is recorded on the blockchain - for anything from tens of dollars to hundreds of thousands.
Players can then use the pets to earn money by winning battles, as well as creating new pets, whose value depends on their rarity. The assets can be traded with other players on the platform, which says it has about 1.5 million daily users.
"It's not just a game any more. It's more like an ecosystem," said Thitadilaka. "You can even call it a country, right?"
The dangers of this speculative ecosystem, and the largely unregulated crypto gaming industry, were brought into sudden focus last week when Axie Infinity was hit by a $615 million heist. Hackers targeted a part of the system used to transfer cryptocurrency in and out of the game.
Axie Infinity's Vietnam-based owner, Sky Mavis, said it would reimburse the lost money through a combination of its own balance sheet funds and $150 million raised by investors including cryptocurrency exchange Binance and venture capital firm a16z.
Sky Mavis' co-founder Aleksander Larsen told Reuters that if he could do things differently, he would have focused more on security when growing the game, which was launched in 2018.
"We were running 100 miles per hour, basically, to even get to this point," he said. "The trade-offs we made maybe weren't the ideal ones."
The hack, one of the biggest crypto heists ever, shone a light on play-to-earn games, a young world largely unknown outside crypto and gaming circles, that's becoming big business.
Players spent $4.9 billion on NFTs in games last year, according to market tracker DappRadar, representing around 3% of the global gaming industry.
Although demand has cooled since a peak last November, gaming NFTs have still racked up $484 million in sales so far in 2022.
Investor interest in NFT-based games has also ballooned, with projects attracting $4 billion of venture capital funding last year, up from $80,000 in 2020, DappRadar said.
"There's so many users who want to interact with the tech," said Larsen, adding that Axie Infinity's revenues exceeded $1.3 billion last year. "It's like you found a new continent like finding America all over again."