Radiant Entertainment announced today that it has been acquired by League of Legends studio Riot Games. The studio also teased "a new game that we’re incredibly excited about," but on a less happy note, said that the alpha test for the free-to-play fighting game Rising Thunder is coming to an end.

“We wish we could say more now, but rest assured you’ll hear more when the time is right. For now, we will be closing the Rising Thunder Alpha on March 18th. Thanks to everyone who participated in the test!” Radiant wrote. As for its other project, the block-based building game Stonehearth, Radiant said work will continue “full speed ahead,” and that the delivery of alpha builds will be maintained at its current pace.

“To everyone who has helped support us by playing Stonehearth and Rising Thunder, backing our Kickstarter, telling your friends, and giving us your feedback: Thank you for helping us make these games as good as they can be,” the studio said. “You have been a consistent source of motivation and inspiration for us, and we look forward to continuing to talk and work with you in the future.”

The announcement isn't entirely clear on the fate of Rising Thunder, but according to Gamasutra, Radiant said that development has been halted as a result of the acquisition—which is unfortunate, because it sounded rather promising in our preview. We're awaiting further confirmation from Radiant on our end and will update when we hear back.

For now, the acquisition is one of the biggest surprises of the year. Riot is one of the biggest studios in the world in terms of personnel, but it has made no such acquisitions during its 10-year history. Riot has hinted that it's working on a game other than League of Legends, but it's unclear whether this acquisition feeds into that unannounced project or will represent something completely new.

Update: Riot has confirmed in an email that the Rising Thunder alpha will come to an end on March 18. The statement on the Radiant website has also been changed to indicate that the game is being "permanently closed."