Among the monsters feared most in Minecraft, the open-world game Microsoft has agreed to purchase for $2.5 billion along with its Swedish distributor Mojang, are Creepers -- exploding, mobile combatants that lay waste to players’ meticulously built virtual constructs. Gamers are now concerned Redmond, known for its corporate hierarchies, relentless product cycles, and laser-like focus on the bottom line is a real-world Creeper that has arrived on the scene to wreck their game, which boasts more than 100,000 players.  

“So from now on Minecraft is no longer an indie game,” wrote user RobertFrans, in a post shortly after Microsoft confirmed the blockbuster deal. “I just hope for the best, that Microsoft understands well enough how the game and the community has evolved together in freedom and creativity, and that messing with that is absolutely not a good idea.”

Other forum members were more blunt. “My heart is bleeding to hear this really happened,” wrote Wuchtbert.

Minecraft diehards’ disappointment was not directed solely at Redmond. Many accused creator Markus “Notch” Persson of selling out.

“If Notch was feeling so pressured by owning such a big thing like Minecraft/Mojang, why didn’t he just hand the company off to someone internal … selling to Microsoft makes no sense,” wrote forum member Henna_Gaikokujin.

In a blog post, Persson confirmed he will leave Mojang when the deal is completed. “I’ve become a symbol. I don’t want to be a symbol, responsible for something huge that I don’t understand, that I don’t want to work on, that keeps coming back to me,” he wrote. “Thank you for turning Minecraft into what it has become, but there are too many of you, and I can’t be responsible for something this big.”

Some analysts suggest the game could lose some of its indie appeal and street cred under Microsoft.

“Minecraft was built by a small company and has a lot of rough edges, but they’re not bad rough edges,” said Brian Blau, a research director at Gartner. Blau added, however, Minecraft players could see some benefits as the game moves to Redmond. “Microsoft can make the underlying technology more easily digestible, and if it continues to support user-generated content there is still a lot of room for growth.”

Microsoft has not elaborated on its plans for the game, other than to promise to continue supporting Minecraft on all its current platforms, including Windows PCs, iOS and Android devices, and on the Sony PlayStation and its own Xbox gaming console. There’s also strong speculation Microsoft will release a version of the game for the Windows Phone platform. In a research note to clients, Nomura Group’s Rick Sherlund said he viewed the deal as an attempt by Microsoft “to better address mobile on a cross-platform basis.”

In Minecraft, players use pick axes, hammers and other tools to populate a virtual world with houses, roads, offices and other structures. They can use creatures spawned in-game, such as cows, pigs, and chickens, for food and materials, while fending off foes like skeletons, spiders, zombies and, of course, Creepers that randomly appear.

Gameplay follows a clock that compresses a single day into 20 real-world minutes. Minecraft was developed by Persson and first released for the PC in alpha in 2009.