Psyonix developed Rocket League over a two-year period for under $2 million, said Dave Hagewood, the studio's founder and CEO, in an interview with the Wall Street Journal. The company kept the lights on by doing contract work for games like Mass Effect 3.
Since the launch of Rocket League in July on PlayStation 4 — where it was available free for the month to PlayStation Plus subscribers — and Windows PC, Psyonix has counted more than 8 million registered players. The studio announced during The Game Awards 2015 that it is bringing Rocket League to Xbox One in February; at the awards show, the game won trophies in the Best Independent Game and Best Sports/Racing Game categories.
Psyonix has supported Rocket League with a steady stream of free and paid downloadable content, including new maps, cars and modes. This week, the company launched the game's winter event, which brought in a hockey-like "Snow Day" mode.
Rocket League got so big that outside parties have reached out to Psyonix about integrating their products with the little game that could. The studio said in September that it had been approached about tie-ins like a film, television show and toy line. That's how the DeLorean from the Back to the Future franchise ended up in the game as an add-on car.
"It didn’t really sink in until they told me they had to get Steven Spielberg's approval," Hagewood told the Wall Street Journal.
The Wall Street Journal reports that Psyonix is currently in discussions to bring other famous vehicles to Rocket League, such as KITT from Knight Rider.
For more on Rocket League, read our review.