Sadly, Rocket ends up stealing the batteries and this caused Ayesha to hire a deadly ravager called Yondu to hunt the guardians down. Oh yea, that ravager raised Peter (Star-lord) and for reasons that will later be explained theirs so bad-blood between Youdu and Peter.
Star-lord later meets his biological father and needs to choose between his and his friends (I wont spoil the reasons behind that). This movie has to do a lot about family, we have sister rivalry between Gamora and Nebula, Star-lord's relationship with both his biological father and Youdu, Rocket having to basically raise (look after) Baby Groot, and well the team itself growing as a family together. This is nice because its somewhat different from other superhero movies. I also think that they wanted to show how the team has grown, I guess since most of them don't have superpowers they need to work together to get things done. Over all great movie, hard to say if it was better than the first.