MapleStory: Idle RPG Survived a Full Refund Offer and Kept Earning
Nexon's tiny idle spin-off made $100 million in 45 days, then offered players every won back after a hidden odds error. Most of them stayed. How a game you barely touch became Korea's biggest mobile hit.
Most mobile games want your full attention. MapleStory: Idle RPG, known in Korea as Maple Kiugi ("raising Maple"), barely asks for it. Your little hero fights by itself, levels by itself and keeps earning loot while your phone sits in your pocket. Players open it about seven times a day, Sensor Tower found, for roughly 12 minutes each time, the most of any top-grossing idle RPG.
That light touch has made it one of the biggest Korean mobile games of the decade. Co-developed by Nexon and Ablegames, it launched worldwide on November 6, 2025, passed $100 million in revenue within 45 days, and had reached about $430 million within 11 months, according to Sensor Tower. Along the way it survived something few games survive: offering every paying player a full refund.
What an idle RPG is
An idle RPG (Koreans call the genre kiugi, "raising" games) automates almost everything. You do not steer your character through fights; you choose upgrades, equipment and skills, and the game plays out the battles. The fun is in watching numbers climb and making smart choices when you check in.
MapleStory, Nexon's side-scrolling PC MMORPG from 2003, is a natural fit. Its cute characters, famous monsters like the orange mushroom, and decades of nostalgia translate easily into a game you play in short bursts.
A launch for the record books
The first 45 days told the story. Sensor Tower counted more than 3 million downloads in that window, with about 67% of revenue coming from Korea, 16.6% from the United States and 7.1% from Taiwan. Among idle RPGs launched in 2025, nothing else earned more.
Advertising helped, but did not do everything: about 40% of early downloads were organic, meaning players found it on their own. Sensor Tower also noted that MapleStory: Idle RPG's audience leaned toward core, PC and console gamers, which suggests many of them were MapleStory veterans coming back in a lighter form.
The refund
Then, in January 2026, players discovered a problem in the game's ability system, where you spend paid currency to re-roll a character's stats. For a period, the highest-grade results simply never appeared. Worse, the issue had been fixed quietly without telling players, what Korean gamers call a "submarine patch".
The backlash was fierce, and Nexon's answer was dramatic. Co-CEOs Kang Dae-hyun and Kim Jung-wook apologised publicly, and Nexon offered a full refund of every payment made from launch on November 6, 2025 until 7 p.m. on January 28, 2026. Applications ran from February 5 to February 15. There was a catch: refunded accounts would be permanently barred from the game, wiping out months of progress. Kang also took on the role of head of the MapleStory division to oversee changes.
Nexon told investors on February 2 that the refund would hit its 2025 results more than 2026, but said it did not need to revise its full-year forecast.
Still on top
The game did not just survive; it kept growing. In March 2026, Byline Network reported it was ranked No. 1 by revenue in Korea, and Sensor Tower's 2026 report lists it among the fastest-growing Korean mobile games of the year, with the $430 million total reached in under a year.
Why it matters
MapleStory: Idle RPG shows two things at once. First, the idle genre is no longer a cheap side business; a well-loved IP can make it as big as any MMORPG. Second, Korean players have become far less tolerant of hidden odds, and they now have the rules to back them: since March 2024, Korean law has required games to disclose the odds of paid random items. WGC's take: Nexon's refund was expensive and painful, but it may also be why the game is still No. 1. In a market where trust is easily lost, offering everything back turned out to be the strongest way to keep players.