The Blockbuster-owned chain, which operates more than 200 stores across the UK, called the pitch in a bid to find new solutions for its media.
The account was previously held by Walker Media, which handles the main Blockbuster account. Walker did not repitch for the business.
Creative duties on the business remain with Cheethambell JWT, which created Gamestation's first TV campaign in December 2004.
The campaign featured a mother's comical attempts to remember the names of video game titles.
Gamestation has appointed Rocket ahead of a busy year for games retailers.
Microsoft recently launched its Xbox 360 console and Sony is expected to launch its PlayStation3 console in November.
Gamestation competes against the market-leader, Game, which operates more than 300 stores.