H1Z1: King of the Kill and its sibling, Just Survive, are a curious pair.

Both games were launched into Steam’s Early Access program more than two and a half years ago as H1Z1, a zombie-themed online multiplayer survival game. But the most interesting part of that product didn’t have anything to do with the undead. It was a tertiary game mode called Battle Royale, where more than 100 players would parachute onto the map, scavenge for weapons and armor and then fight to the death. It was so popular that for months after it launched getting into a match was nearly impossible.

A year after it came out, developer Daybreak Game Company split H1Z1 into two different games. The first was called H1Z1: Just Survive and was later renamed Just Survive. It retained the original’s focus on surviving in a post-apocalyptic, zombie-filled world. The other game was called H1Z1: King of the Kill. It leaned into the fast-paced, last-man-standing style of gameplay found in the original Battle Royale mode. It’s been the more popular product by far, and has gone on to become a premiere competitive game for both consumers and esports professionals.

To date, it’s the only game in Steam’s Early Access program to get it’s own televised prime-time special.

King of the Kill’s gameplay should sound familiar. That’s because it shares a lineage with Steam’s hottest title right now, a little game called Playerunknown’s Battlegrounds. It was Brendan “Playerunknown” Greene who consulted on and helped to create the Battle Royale mode that would go on to become H1Z1: King of the Kill.

And yet, even with the explosive growth of Battlegrounds — the first game to overtake Valve’s own Dota 2 in concurrent players in years — H1Z1: King of the Kill has held its own. Since June, according to Steamcharts, it’s barely lost any players at all.

The challenge for Anthony Castoro, Daybreak’s new general manager on the project, is to keep King of the Kill’s playerbase happy and get their numbers growing again. He says that his team sees the success of Battlegrounds as a “huge opportunity.”

“This is a classic fast-follow scenario,” Castoro said, referring to the success that Greene and Bluehole have had in the last six months. “But we invested in the idea first, we built it out, we built up an audience, and we’ve had a lot of success.

“We’ve sold millions and millions of units of the game, and if you look now at Steam’s concurrency you’ll see that two of the top four games are King of the Kill and Battlegrounds, both in this Battle Royale genre. So the fact that Battlegrounds is doing so well, we see that as an opportunity both to differentiate on our gameplay and also to introduce people to the genre and get them to start looking around for other experiences that are interesting.”

The team at Daybreak is differentiating itself in a number of ways. A big change came with this week’s combat-focused update. It revamped many of the game’s weapons, changing things like their range and recoil but also how the game’s aiming mechanics work. Castoro says he’s trying to get his team to bring King of the Kill back toward the mechanics of a traditional first-person shooter.

But the other part of his team’s vision is in speeding up the core gameplay experience. When H1Z1 first launched, rounds of Battle Royale might take 40 minutes to play out. Now, Castoro says, his team has gotten King of the Kill closer to 28 minutes on average. By tinkering with things like the speed that the arena closes in on players, he’s confident that they’ll be able to get it down closer to 22 minutes or less.

The changes won’t stop there, he said. The next phase of development is to alter how players gain power, in the form of weapons and vehicles, throughout the course of the game.

Castoro said that his team wants to give the game a kind of three act structure. In the beginning, players will hit the ground and quickly grab a simple weapon: a pistol, a rifle or even a bow and arrow. In the second act they’ll engage with other players, get a few kills and begin to move across the map with the help of a scavenged vehicle.

“In the third act,” Castoro said, “our goal is to end in a spectacle of mayhem.”

That spectacle will be achieved with a bevy of airdrops all over the map, each of them filled with high-powered weapons, armor and vehicles. These second- and third-tier weapons will include laser sights and grenade launchers. They will reward players who have the in-game skills to stick it out into the later rounds, but they’ll also contribute to the viewer’s experience at home.

“Streaming has been really important to the success of H1Z1,” Castoro said, “and the viewability of our game has always been key to its success. Part of the fun of watching these games has been waiting to see what’s going to happen, who’s going to make the best play. When someone outsmarts someone else or outplays someone else, that’s really the key moment. By introducing these tiered weapons and power progressions into the game, we’re really upping the stakes on the watchability of that experience.”

Castoro said that there will be more details on coming changes in H1Z1: King of the Kill during TwitchCon in October. That’s when the next invitational tournament, with a prize pool of $500,000, will be broadcast live from Long Beach, California.

But questions still remain.

For one, where’s the console version of King of the Kill first promised in 2016? Castoro says he plays it every day against live competition online, but for now his team is holding it back until the PC version is fully fleshed out.

And when will H1Z1: King of the Kill, or its sibling Just Survive, leave early access? Castoro wasn’t able to give us any answers.

“We’re very focused on getting the game to a point where we’re confident in coming out of early access as soon as possible,” Castoro said. “The updates, the pace of content releases, the discipline within the development organization and the investment in the technology are all about getting the game to a point where we feel proud to say that this game is complete. I’m not going to give you a date right now, but I will tell you that is something that we are highly focused on and is something that we’ll be talking about in the coming months.

“The games are a labor of love. The team is really passionate, and it’s easy for people to say, ‘Oh, look at this other game [Battlegrounds]!’ But we define our own success, and if we continue to grow and as we look forward to these updates and changes there’s going to be a lot to talk about at TwitchCon.”