"Fortnite's" spin-off Battle Royale mode, which was inspired by the immensely popular "PlayerUnknown's Battlegrounds," had a very strong start. The game announced today that more than one million players participated in the launch day of "Fortnite Battle Royale."

On Twitter, "Fortnite" developers announced that over a million players "partied on the Battle Bus" during the game's first day. The game launched on Tuesday despite resistance from the developers of "PlayerUnknown's Battlegrounds," which is the game responsible for the increasing popularity of the Battle Royale genre among gamers today.

The team behind "PlayerUnknown's Battlegrounds," Bluehole Studios, took issue that Epic Games, the creator of the Unreal Engine that the studio used to power its massively popular game, released a game very similar to theirs.

"There are a lot of different issues but everyone else that released a battle royale game mode made their own thing," Bluehole vice president and executive producer, Changhan Kim, told PC Gamer. "But it was Epic Games that made this game that is similar to us that has similar elements, and that's the concern, that it was Epic Games."

"Fortnite" has some advantages over Bluehole's first person shooter, as Epic game's shooter is a free-to-play game and available to multiple platforms. "Battlegrounds," which is still on its early access, is a paid-game and is currently only playable on the PC. An Xbox One version is still in the works.

"Fortnite" which has a core gameplay that involves gathering items and building fortified structures to fight waves of enemies. Dozens of players are dropped on a map to fight each other, with the last person standing being declared the winner.

Despite being in early access, "Battlegrounds" recently broke the Steam record for most number of concurrent players with over 1.5 million online players, beating the previous mark set by Valve's own "Defense of the Ancients (DOTA) 2."