TL;DR, Marvel is basically just printing their own money at this point. I’ll fully admit, when I heard Marvel was doing a movie featuring a sentient, anthropomorphic raccoon sociopath I had my doubts but they knocked it out of the park.
This is a movie that pretty much has it all. With comedic bits strewn liberally throughout the film, it has both its lighthearted moments as well as its serious ones, both of which come on you with startling joy and surprising stealth and then hit you like a brick between your eyes. The action was good, the effects awesome. While I can’t say I’ve EVER read a comic with any of these characters aside from Thanos, and thus can’t speak to how accurate they are to the comics, I’m very happy with this addition to the MCU and I’m sure we’ll be seeing them again in Avengers 3 (not a spoiler, really, we just already know A3 is going to involve Thanos who is tied pretty tightly to the Guardians so it seems like a likely bet that’s when we’ll see them next).
Go see this movie in the theater, then see it again in the theater.