Indie smash hit Peak has sold over 4.5 million copies so far. 

That's according to the Game Discover Co newsletter, which reports that the title from developer Aggro Crab has reached this sales milestone three weeks after its initial June 16th release. Peak initially reached two million sales within nine days of its launch. 

Looking at SteamDB data, the game has reached an, er, peak of 114,492 concurrent players on Steam. 

Speaking to Game Developer shortly in the wake of Peak's release, developer Aggro Crab said that the game's early success was unexpected. 

"We thought if we were lucky it would eventually do half as well as Content Warning," studio head Nick Kaman said. 

"We broke even in the first few hours. Now that a week has passed, we're at 1.6 million copies. It's absolutely bonkers and none of us expected it, we are freaking out. We knew we had a decent shot of success because of our platforms but this level of attention has been completely unprecedented for us. We're attributing this win to the Power of Friendship."