The only reason I paid the $9.50 to see it in theaters was for Rocket Raccoon, so I am completely and totally biased.

By the way, don't take anything I say in this review too seriously. I am a terrible movie critic, who is infamously hard to please. I'm sure the film is already breaking box-office records and is immensely popular, so my opinion really isn't important. I had never heard of the comic this was based on until the movie came out, and didn't even know Rocket Raccoon was anything but a fighting-game character until then. Plus, I'm not a fan of Marvel, DC or comic books in general, so I'm way outside the target demographic for this. But I'm a good Furry, so I couldn't not see the movie with the talking animal.
Beyond that, all the previews I saw with him showed a realistically modeled, seriously played, tiny furry baddass, and I really wanted to see him in action.

My overall appraisal is that the movie was ridiculous. Even for a summer-popcorn-muncher film, it felt like a throw-away film to cash in on the current fad for super-hero movies. Which, I guess can be expected from Marvel at this point. This is basically another Avengers movie, just with a Raccoon and a giant plant and an army of CGI animators to fill in all the gaps and make it look shiny for the audience.
Each character had a motivation, but they spent so little time expanding on it, and most were so cliche, that they felt forced and lacked any impact. But I do give props to Dave Batista and Bradley Cooper for how they carried their characters. The femme fatale was standard fair and pretty forgettable, and Quill was more interesting and better acted by his ten year old incarnation than his adult version. But he was better than the "frat bro who didn't grow up" archetype that I first thought he was going to be from the previews.

Vintage music plays a part in the film, particularly as it pertains to Quill, but the way they kept cutting it into the film felt like they were trying to force a feeling of nostalgia or something. It got old after the second time.

Even though I don't regret going to see it, and it's certainly better than most of the other movies I've seen this season, it had no surprises, cookie-cutter villians, and I just found myself unable to engage with the movie. That's the biggest reason everything felt so forced to me - I just couldn't get immersed in it. I was continually waiting for the other characters to get out of the way so I could see what they were going to have Rocket do next.
The only parts of the film that grabbed me emotionally at all, were the opening scene (I won't spoil anything), and the bit near the end inside the "Groot-ball", which itself would have made more of an impact if there had been some explanation beforehand of how it worked and what could happen. As it was, you just got a "Oh...I guess this is happening now". The main character of Peter Quill was better acted by the ten year old boy than his adult counterpart, but that may have more to do with my ambivalence to his style of anti-hero than to the actor's actual performance.

With a lot of movies, I think I set them up for failure before I even enter the theater, and make all my prophesies about their quality self-fulfilling ones.
I went into the film wanting to see the Raccoon with a big gun and bigger attitude blow some stuff up, and didn't expect to enjoy the rest of the movie.
I walked out of the theater acknowledging that if it hadn't been for Rocket and Groot, I wouldn't have liked the movie at all.

On a side note, I really like that red longcoat Quill wears. And if I ever meet Rocket Raccoon, I'm buying him a whiskey. Or two. Or we can just keep drinking and see how many it takes before I can give the angry furball a hug without getting my face blown off...