Microsoft-owned "Minecraft" continues to be a massive success.

The monthly player count crested 91 million this summer, an increase of nearly 20 million players across 2018.

Over 154 million copies of the game have been sold, making it the second highest-selling game of all time.

"Minecraft" continues to be one of the most popular games ever made.

The creation/survival indie game that Microsoft purchased back in 2014 for $2.5 billion has now sold over 154 million copies and enjoys a monthly userbase of over 91 million players. The latest numbers were revealed by Microsoft over the weekend — they're worldwide statistics, which include the Chinese version of "Minecraft."

Those numbers are exceptional, even by "Minecraft" standards.

"Tetris" holds the title as highest-selling game of all time — and continues to sell — with "Minecraft" and "Grand Theft Auto 5" in second and third place, respectively. Richard Drew

The game has been a notoriously explosive phenomenon since early in its life; "Minecraft" started as a work-in-progress game, made by a single man (Markus "Notch" Persson). It had rudimentary graphics and controls. It was only available on PC. It was prone to breaking, because it was an unfinished game being made by a single person.

And yet, millions of people bought and played that early version of "Minecraft." When Microsoft bought the game back in 2014, the tech world was surprised and confused by the purchase. Persson did not join Microsoft.

But clearly that early success has persisted under Microsoft's care. Just to compare, more people play "Minecraft" on a monthly basis than the populations of France, UK, Italy, or South Korea.

But why is it so popular? We're talking about a game that looks like this:

"Minecraft" is available on nearly every game platform available, including the Nintendo Switch. Nintendo

Think of "Minecraft" as virtual LEGO.

It's a system for fitting pieces together to create something — sometimes amazing somethings — from nothing. "Minecraft" provides endless building blocks and a blank canvas. It's up to you to create something incredible, or silly, or referential, or whatever, using the tools it provides. The tools are blessedly user-friendly, as are the systems for employing those tools.

With that in mind, it's not hard to understand why "Minecraft" has been such a hit. That it's graphically rudimentary and simple to play just makes it all the more accessible to a large audience — over 91 million people every month, apparently.