Fortnite’s Battle Royale mode is proving popular, it seems. Developer Epic Games announced on Twitter that the game reached 3.7 million players on Sunday, October 8. At its peak that day, Battle Royale had 525,000 concurrent users, Epic added.

Those figures cover North America, Europe, and Oceania, and are presumably the sum of players across Xbox One, PlayStation 4, and PC. The numbers are huge, and even more evidence that people are excited about the Battle Royale experience, wherever they can find it.

Fortnite Battle Royale’s player figures are massive and impressive, but they pale in comparison to the game it is often compared to, PUBG. That game had an absolutely astonishing 1.93 million peak concurrent players today, according to public Steam data.

Battle Royale continues to grow. It reached 1 million players on launch day in September. As for the base game, Epic announced in July that 500,000 people bought one of the game’s paid tiers just days after it launched.

Fortnite’s base game is available starting at $40 right now on PlayStation 4, Xbox One, and PC through the Founder’s Pack. In 2018, the game will adopt a free-to-play business model. As for Battle Royale, the game is completely free on all platforms.

Fortnite’s Battle Royale mode bears some similarities with PUBG in that it’s a 100-player, Hunger Games-style, fight to the death, last-player-standing, white-knuckle experience. PUBG developer Bluehole recently responded to Epic overall Fornite: Battle Royale, calling out the similarities and threatening “action” against Epic. Nothing has come to light as of yet, it seems, though it will be interesting to see what happens in the future. For more, check out GameSpot’s video feature on the subject embedded above.