A little while back, we talked about a mobile game called Fallout Shelter, Bethesda’s mobile management spin-off to its popular open-world adventure games. Even though the franchise was new to the mobile front (releases had previously come out for PC and game consoles), Shelter had no problem weathering the storm, easily overtaking King’s Candy Crush Saga since its arrival last month. But now, its success is stronger than ever – and that’s good news for the mobile front and Bethesda alike.

GameZone has reported that the mobile game, where players manage a group of “happy” characters through underground living, has managed to gross more than $5.1 million in its first two weeks – a first for the developers at Bethesda.

Originally, the intent of Fallout Shelter, which was released during the company’s press conference at the Electronic Entertainment Expo, was to build hype for its forthcoming sequel Fallout 4, set to debut on November 10 for Xbox One, PC and PlayStation 4. But it appears that the game has created its own mantra, one that players can easily get into. Plus, with its fair payment system (there’s a lot to offer on its free-to-play set-up), that indicates that players are actually willing to pay to get more out of it.

Said SuperData on the game’s surprising mobile success, “While we’ve seen mobile spin-offs based on AAA game franchises before – Call of Duty: Heroes, Halo: Spartan Assault and Heroes of Dragon Age – Bethesda managed to maximize exposure and reap the benefits. More significant than the publisher’s success is the notion that core gaming fans proved to be willing customers for a free-to-play mobile game.”

It continued, “By emphasizing unobtrusive monetization and offline playability, Bethesda managed to earn the respect of a consumer group that is otherwise highly critical of free-to-play monetization. The game’s success further underscores the value of a strong franchise in the otherwise crowded mobile games market.”

Plus, on top of that, Shelter has become its own hype machine for Fallout 4, which should be an immense success when it releases later this year.

But the publisher isn’t just reaping success on the mobile front. Its latest console release, the online-only adventure The Elder Scrolls Online, has sold over 138,000 digital copies – not a bad number for a game that requires a consistent connection. And it’s got a killer line-up of console/PC games lined up for next week’s QuakeCon in Dallas, Texas, where Fallout 4 and the forthcoming Doom will both have a huge presence.