The in-beta MOBA — or, as Blizzard calls it, the "online team brawler" — currently contains 33 heroes culled from franchises like Diablo, StarCraft and World of Warcraft. The developer is also testing another six or so internally.
Browder, who also directed StarCraft 2, said that Blizzard will continue to add characters to the game, and Heroes of the Storm's eventual launch won't be dependent on the roster.
"We're just going to keep adding heroes forever until we get sick of it and stop at this point," Browder said. "There's no secret number, and there's no number that determines when we launch."
According to the game's director, Blizzard is applying a similar strategy to Heroes of the Storm's maps.
"We're gonna keep adding more, definitely the rate of growth on maps is not gonna slow or stop until we say so," he said. "Until somebody tells us, 'Dude, too many maps' or whatever. We're adding them as frequently as we can, and we're going to keep adding them as frequently as we can, even after launch."
The idea, Browder said, is to keep the game expanding, just as it has in the beta.
"This is the pace that we're hoping to continue developing at going forward," he said. "We're gonna add game modes, we're gonna add new heroes, we're gonna add new battlegrounds. Our goal for this game is to communicate with our audience to the best of our ability that you haven't seen anything yet. We don't want this game to become stale. We do not want this game to become repetitive. We want this game to constantly evolve."
Earlier this month, Blizzard introduced the $39.99 Heroes of the Storm founder's pack, which grants purchasers access to the Mac and Windows PC game's ongoing beta — among other things.