'Guardians of the Galaxy' director James Gunn says he is 'terrified' to release the Marvel movie. Gunn penned an open letter to his fans on Facebook to discuss his hesitations about the movie, reported Digital Spy.

"This is essentially my last week of actually making 'Guardians of the Galaxy'. It's been two years straight and I'm starting to become terrified of actually having to stop," Gunn posted on Facebook.

Gunn added that while he has been critical of directors who tinker excessively with their movies, he can now see himself falling into that category.

"I swear, I've gotten angry with filmmakers like Ridley Scott and George Lucas who can't let go of their old films and want to keep going back and offering up different versions, but I can easily see myself doing that now," he said.

"There isn't much left to do. I'm still playing with the sound mix and the 3D and the DI (digital intermediate - basically the colour-timing) - and there are some outstanding visual effects shots.

"I think the Marvel producers are starting to understand my almost psychotic inability to be happy with anything, and to pick apart things to the very bitter end. They're going to have to tear this movie from my bloody grip," he said.