Microsoft has closed the previously much-rumored deal to acquire Mojang, the small Swedish company behind the massively popular videogame franchise Minecraftfor $2.5 billion.

If you’re not a gamer, or the parent of one, you may not know Minecraft, but trust me, the little kids understand. It’s huge, one of the biggest independent game franchises in the world. The game has blocky, Lego-like graphics that are far from state-of-the-art in their style, but it hasn’t stopped the game’s rise over the past few years. It provides a rich and addictive experience, allowing a player to create their own world, down to the geology and plant life, then defend their virtual home and people against various challenges.

The price of the deal is bigger than previous reports had suggested it would be, and may reflect the long-time and noisily proclaimed resistance of Mojang’s founder Markuss Persson to being bought by anyone. He cancelled work on a version of Minecraft for Oculus Rift, the virtual-reality technology, after it sold to Facebook earlier this year for $2 billion.

Markus Persson Mojang founderPersson, whose online handle is “Notch,” posted a goodbye letter, saying he’ll depart Mojang as soon as the deal is closed, to focus on the sorts of “small web experiments” he enjoys, rather than trying to build and run a big brand within a much bigger company. The decision, he wrote, is “not about the money. It’s about my sanity.”

For Microsoft, the deal will give it a huge game franchise to bolster its stumbling Xbox One game console. Though new CEO Satya Nadella has said games aren’t core to the company’s future, and wiped out most of the company’s Xbox Entertainment Studios venture in July as part of 18,000 in broader layoffs, the deal could layer on a huge online community of players. It may also deny the game to Xbox’s main competitor, Sony’s PS4.

That said, in a post and video on Microsoft about the deal, Xbox Head Phil Spencer wrote that: “Minecraft adds diversity to our game portfolio and helps us reach new gamers across multiple platforms. Gaming is the top activity across devices and we see great potential to continue to grow the Minecraft community and nurture the franchise. That is why we plan to continue to make Minecraft available across platforms – including iOS, Android and PlayStation, in addition to Xbox and PC.”

Minecraft has been available on Microsoft’s older-generation Xbox 360 for a couple of years. In that time, Spencer wrote, more than 2 billion hours of the game have been played on Xbox Live, the company’s online game network, where Minecraft is the top online game.

The deal may also help Microsoft’s mobile division, which is still trying to gain footing against Apple’s iPhones and iPads and the many smartphones and tablets using some version of Google’s Android operating system. Mojang had previously declined to create a Minecraft version for Windows Mobile, saying the market share wasn’t big enough to warrant the investment of development resources. Presumably, Persson and his small staff will have plenty of resources to create that version of the game.

News of the deal sent Microsoft shares down less than 1 percent in early trading to $46.28 per share.