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.