Finnish developer Seriously has revealed that its puzzle game Best Fiends earned over $3 million in revenue during December 2015, its largest revenue month to date.
This is thanks to its recent Race Against Slime 2 charity campaign, which enlisted more than 20 YouTube stars - and The Ellen DeGeneres Show - to take part in a competition using the game.
The campaign raised $250,000 for charity bringing its lifetime total donated to $350,000.
The move also saw the game downloaded 2.6 million times, pushing the all-time downloads to 25 million, with a daily active player count of 2.1 millon.
Seriously also released an infographic on its progress in 2015, which reveals a $25 million gross revenue to date, with 2.1 million daily active users.