when was this movie released?
July 21, 2014 at the Dolby Theatre and August 1 in  United States
Guardians of the Galaxy (film)
"Guardians of the Galaxy" premiered at the Dolby Theatre in Hollywood on July 21, 2014, and was theatrically released in the United States on August 1, as part of of the MCU. 
who plays bad guy in guardians of the galaxy Thanos
wiki:18586530
Guardians of the Galaxy (film) [SEP] Introduction
In addition to an original score by Tyler Bates, the film's soundtrack includes several popular songs from the 1960s and 1970s chosen by Gunn. Post-production was completed on July 7, 2014. "Guardians of the Galaxy" premiered at the Dolby Theatre in Hollywood on July 21, 2014, and was theatrically released in the United States on August 1, as part of of the MCU. The film became a critical and commercial success, grossing $772.8 million worldwide and becoming the highest-grossing superhero film of 2014, as well as the third-highest-grossing film of 2014. The film was praised for its screenplay, direction, acting, humor, soundtrack, visual effects, and action sequences.