One of the most lucrative games ever released for smartphones is coming to an end — at least in its English form.

Developer Mixi revealed today that it is shutting down the English version of Monster Strike, the mobile arcade-style role-playing game where you fling balled up monsters at one another in combat. While the game is still the No. 2 highest-grossing app on Apple and Google app markets in Japan, it has failed to replicate anything close to that ranking in Western territories. That relative lack of success directly led to Mixi deciding to turn out the lights on August 1 — although, players will no longer have the option to download it beginning July 2.

“Unfortunately, despite our best efforts, the English version of Monster Strike just wasn’t the success that we thought it would be,” reads a Mixi blog post. “Sustaining the game at a satisfactory level has become difficult — no matter how much we want to keep it going.”

Monster Strike is the No. 511 highest-grossing game on Google Play in the United States, according to market-intelligence firm App Annie. But it isn’t even in the top 1,000 most downloaded apps on either Android’s app store or the iOS platform.

Moving forward, the other versions will still operate, but fans who have accounts on the English game won’t have the option to transfer them. But Mixi is promising a few more events and content drops for Monster Strike before finally shuttering the app for good.

“We’re sorry for not being able to continue the game and letting down your expectations,” reads the developer’s blog. “This game and you, our players, have been a part of our lives for almost three years. The immediate reaction is a mix of sadness and anger, which we completely understand. Please know that this is an extremely painful decision for us, too.”