After nearly a year as an independent studio, the developer was acquired by Vivendi Games in January 2006 and placed under Sierra Entertainment.

Turning to game development only, the studio continued development of games from its time as Sammy Studios, including the Western horror shooter Darkwatch.

In January 2006, it was announced that Vivendi Universal Games had acquired the studio.

Following the completion of Deadpool, Activision laid off 40 full-time employees from High Moon Studios that worked on the project.

Activision stated "Activision Publishing consistently works to align its costs with its revenues – this is an ongoing process, with the completion of development on Deadpool, we are taking a reduction in staff at High Moon Studios to better align our development talent against our slate.