In a surprise move, publisher Epic Games announced that it is acquiring Psyonix Inc. The San Diego-based developer is best known for creating the hugely popular multiplayer game Rocket League.

The deal, the terms of which wasn’t disclosed, is expected to finalize at the end of the month or in early June. Psyonix has been around since 2001, working on a handful of its own games across various platforms — but at 57 million players, Rocket League is its biggest hit so far. The studio also has a lengthy history with Epic, helping the company out on development for Gears of War and Unreal Tournament games. Psyonix currently has 132 employees.

As part of the acquisition, the two companies also announced that the PC version of Rocket League will be moving off Steam and into the Epic Games Store in late 2019. In a press release, they said the game will still be available for purchase on Valve’s storefront until that day comes. After the move, Psyonix will continue supporting the Steam version for all existing customers.

After reaching out to Epic for clarification about this process, a representative said that owners of Rocket League on Steam (including its DLC) will “always” have access to the game. GamesBeat also asked if Rocket League owners would be able to purchase DLC on Steam after the game moves to the Epic Games Store. “Long-term plans are still in motion and will be announced down the road.”

In a new blog post, Psyonix promised that, other than shifting to the Epic Games Store, this won’t affect any future plans for Rocket League.

“We’re still committed to providing Rocket League with frequent updates that have new features, new content, and new ways to play the game for as long as you’ll have us,” the post reads. “In the long-term, we expect to bring Rocket League to the Epic Games Store and to leverage our new relationship to grow the game in ways we couldn’t do on our own before. We believe that bringing Rocket League to new audiences with more support is a win for everybody.”

“Psyonix has always been a part of the Epic family, and we”re happy to make it official. We have great respect for how Psyonix has built an excellent team and an incredible community around Rocket League,” said Epic Games founder and CEO Tim Sweeney in a statement.

Update, 2:39 p.m. Pacific with comments from Epic.