Guardians of the Galaxy failed to pass the Bechdel, Russo and race test.
There was only one instance in Guardians of the Galaxy where women directly spoke to each other and that was near the conclusion. For example, Gamora and Nebula had a brief conversation while they were fighting, but because they kept mentioning Thanos and Ronan, their conversation (and thus the film) did not pass the Bechdel test.
As to why Guardians of the Galaxy did not pass the race test, there was only one non-White character in the film so Guardians of the Galaxy was obviously unable to fulfill the requirement of at least two non-White characters speaking to each other without mentioning White people, and the film did not pass the Russo test because there were no identifiable LGBT characters.
*The Bechdel test entails three requirements:
1. It has to have at least two (named) women in it
2. Who talk to each other
3. About something besides a man
**The Vito Russo test entails three requirements:
1. The film contains a character that is identifiably lesbian, gay, bisexual, intersex and/or transgender
2. The character must not be solely or predominately defined by her sexual orientation, gender identity and/or as being intersex
3.The character must be tied into the plot in such a way that her removal would have a significant effect
***The race or people of color (POC) test has three requirements:
1. It has two people of color in it
2. Who talk to each other
3. About something other than a White person
****Just because a film passes the Bechdel, Russo and race test does not mean that it is not sexist, heterosexist, racist and/or cissexist, etc. The Bechdel, Russo and race test is only a bare minimum qualifier for the representation of LGBTI individuals, women and people of color in film. The failure to pass these tests also does not identify whether the central character was a woman, a person of color or a LGBTQI individual and it does not dictate the quality of the film.