It has been downloaded over 100,000 times on Android devices.
It has also gained social media attention and was among the top mentioned topics on Twitter at the end of last month and early this month.
Popular Japanese gamer Lucian said it attracts players because of its ease of access.
Titan Hunters was launched at the end of March.
Unlike other NFT games, it is free, and those who want to play to earn need to link the game with their e-wallet.
Japan has among the largest number of players and developers of electronic games globally.
At 70 million players, the game has a quarter of the numbers Sony, Nintendo and Sega do.
Titan Hunters CEO Vu Duy Tiep said Japan is a market with high competition and players there are "pretty picky."
The game has been downloaded 150,000 times across all platforms with around 50,000 active players daily, 75 percent of them in Japan, he said.
"We aim to reach the European and U.S. markets next."
In Vietnam, some players have been complaining that the game has bugs and their gameplay experience is not "smooth."
Axie Infinity was the first NFT game developed in Vietnam to become internationally popular.