So I am playing the game because it was free on my PlayStation plus premium and I got a reward on my PlayStation app for playing it. I’ve kind of gotten into Guardians of the Galaxy now but I went into the game basically blind. I knew who Rocket Raccoon was and Groot but that was about it. So I do understand that Rocket understands what Groot is saying and Groot just says I am Groot.
The game is separate to the movies. There’s nothing to need to know before hand. Plus the movies are based on comics anyway and didn’t require prior knowledge to watch them, the game is also based on the comic characters. The origins of the characters in the game differ somewhat to the movies as well so there isn’t any benefit or advantage you’re missing by not having seen the movies.