Sony’s free-to-play mobile MMO “Fate/Grand Order” has grossed an estimated $3 billion in player spending on iOS and Android since its launch in August 2015, according to market intelligence company Sensor Tower.

To put that figure in perspective, Sensor Tower said it’s the equivalent of a PlayStation 4 title selling 50 million copies at $60 each. It’s also five times what PS4 blockbuster “Horizon: Zero Dawn” grossed after selling 10 million copies at full retail price.

“Fate/Grand Order” is based on the “Fate/stay night” visual novel and franchise by Type-Moon. Published by Sony subsidiary Aniplex, it’s a turn-based tactical RPG where players summon and command powerful servants to battle their enemies. Its narrative is also told in a visual novel-style format.

About 82% of “Fate/Grand Order’s” player spending comes from Japan, Sensor Tower said. That amounts to about $2.6 billion of the total revenue. Chinese players on iOS spent an estimated $360 million or 12%, while the U.S. ranks third with $90 million or 3%. “This is still a significant amount of revenue for a market where the title’s source material is considerably less well-known than in Asian territories,” Sensor Tower said.

“Fate/Grand Order” was the No. 2 ranked mobile game for global revenue last month at $84.3 million. It placed No. 59 in the U.S.