Seriously, the mobile game studio by former Rovio execs, has secured an additional $5 million from existing investors Upfront Ventures, Sunstone Capital and Daher Capital.

“The additional funding gives us extra firepower to extend our talented team of 13 people as we take our strategy of creating global entertainment brands ‘mobile first’ to a new level,” said Chief Executive Andrew Stalbow in a statement.

Stalbow and Chief Creative Officer Petri Järvilehto co-founded the game studio last year after working together in Finland for Rovio Entertainment, the company behind the mobile franchise Angry Birds.

Seriously’s business operations are in Santa Monica while game development is done in Helsinki. Its first game, Best Fiends, launched last month. A trilogy has already been announced.

With the latest round, the studio has raised $10 million to date. It plans to open a Series A round next year.

Staff reporter Melissah Yang can be reached at [email protected]. Follow her on Twitter @MelissahYang for the latest in L.A. tech news.