Digital Extremes announced today that Warframe is getting close to hitting the 50 million players mark.

The cooperative shooter came out back on March 25, 2013 for PC. The free-to-play game is celebrating its sixth anniversary today. PlayStation 4 and Xbox One versions followed later that year

Warframe was not an instant success. It took years to develop a following, but it began to see steady growth that slowly turned Warframe into one of the most popular free-to-play games. And Warframe gives players plenty of ways to spend real money, including on things like cosmetics and extra inventory space.

2018 was a big year for the game. Warframe launched for Switch on November 20, and Digital Extremes released 26 updates throughout the year. Back in March 2018, Warframe had 38 million registered users. The game has grown by almost 12 million players in the last year.

Warframe is a free-to-play alternative for those looking for a a shooter RPG experience with friends. Other similar games, including Destiny 2, The Division 2, and Anthem, have an upfront cost. In the free-to-play world, Waframe has to compete with other kinds of RPGs, including Path of Exile.

“Warframe’s dev team is deep in development with the Plains of Eidolon Remaster and Gas City Remaster updates — two gameplay and graphical overhauls that renew both areas — and exciting, game-changing updates like The New War and Railjack,” Digital Extremes noted in a release sent to GamesBeat. The studio is not slowing down on making new experiences for Warframe, and that could help the shooter continue to grow through 2019.