From Tokyo to San Francisco, mobile game studios have sparred for years to captivate a fickle audience, fostering an overlooked problem — the average title has become so huge that players can no longer fit more than a few on their phones.

Japanese games publisher Gree expects an impending reckoning over escalating costs and ballooning file sizes, as developers pack their games with increasingly intricate graphics, voice acting and larger storylines, all to get players spending. That’s creating a winner-takes-all situation that could winnow out smaller studios in the coming years, Gree Senior Vice President Yuta Maeda said in an interview. The situation will only get worse as console veteran Sony — no stranger to space-hogging hits — prepares to invade the mobile arena.

"Production of mobile games can’t avoid becoming more complex, time-consuming and larger-scale, which will inevitably result in bigger app sizes,” Maeda said. "Companies that survive in the market will only be the ones that can keep up with that trend.”