Thunderful Group has since acquired further developers, the publisher Headup Games, and the consultancy firm Robot Teddy.

Although the two studios were separated by the Göta älv, Sigurgeirsson and Lyngeled met frequently due to the small size of Gothenburg's indie scene.

[2][4] Sigurgeirsson, Lyngeled and Bergsala Holding decided to merge the two studios and created Thunderful as their parent company in December 2017.

[5][6] The company was jointly owned by the founding parties: Bergsala Holding held a 50% stake and Sigurgeirsson and Lyngeled 25% each.

Valiente subsequently became the managing director for Rising Star Games, replacing the departing Martin Defries, while retaining his previous positions.

[15][16] By November 2020, Thunderful Group was preparing an IPO via the Premier Growth Market of the Nasdaq First North, expecting to raise 750 million kr.

[18] Thunderful Group announced that it would acquire German publisher and developer Headup Games in February 2021 in a deal worth up to €11 million.

[19] With the acquisition, Headup's founder and managing director, Dieter Schoeller, is to become Thunderful Group's head of publishing.

[22] In September 2021, Thunderful Group acquired Madrid, Spain-based developer Stage Clear Studios in a deal worth up to €2.5 million.