Obsidian's upcoming espionage RPG, Alpha Protocol, has been pushed back from a Spring debut to a Summer release as further polish and tweaks are applied to the game.

The news comes via MTV Multiplayer, who spoke to assistant producer Matthew Hickman about why that game had been pushed back, letting slip that another delay had occurred.

According to Hickman the ongoing delays are part of Obsidian's efforts to polish the game up to a proper standard and the developer has mostly spent time on tweaking the lighting, revamping the inventory screens and "bringing the whole quality level up."

"We really wanted to polish the game up, make it everything Obsidian planned it to be, and give the consumer a very polished game," Hickman said.

Alpha Protocol, which was originally set for a 2009 release, tells the story of a CIA operative who goes undercover when tracking down some missing missiles and discovers a huge conspiracy in the process. It's pitched very much as an action-RPG, with the third person shooting supported by an impressively realised stats system. Players are able to research enemies and friends, buy new equipment and form a network of contacts in between missions.

Alpha Protocol will now be released on Xbox 360, PS3 and PC this summer.

We had a look at the game at GamesCom 2009 and were mighty impressed, so check our Alpha Protocol preview for more information and then let us know what you think in the forums.