I saw the movie this morning and overall it is fantastic. I am definitely going to see it again. I heard that 3D wasn't that good except for the long space shots. I would say the movie is good for 8 year olds and above: shit, asshole, subtle masturbation joke, cartoon violence with little gore. There is a dying/dead mother storyline that could be tough for little ones.
The soundtrack - if you like 70's and 80's rock, you will adore the music in this movie. It is actually a plot point so enjoy the meta.
CGI characters - if you told me twenty years ago pixels would make me cry, I would say you're crazy. Seriously, Groot and Rocket Raccoon steal the whole movie!
Heart - this isn't a movie about heroes or winners who are amazing at everything they try. It's just a bunch of messed up folk who wind up doing the right thing. There is also a bit of hope mixed into the pain. I liked the lack of cynicism and cruelty.
Chris Pratt - he is really excellent as Peter Quill. Like a combo of Han Solo, Arthur Dent, and Andy Dwyer. He sells all the notes from comedy to drama.
Dax the Destroyer/David Bautista - from the commercials, I thought he would just be the head busting tank of the group but he was surprisingly funny!
Set design/special effects - great locations, amazing spaceships which look so original and vibrant.
MCU connections - Thanos and The Collector show up so there is a vague web of something going on that ties to the other movies.
The Not So Great
Gamora - she has a back story and a lot of dialogue but I didn't really connect with her character.
Ronan - I know Loki is a tough act to follow but this guy is like high drama Darth Vader. I love the actor but maybe he's such a face actor, all the makeup sucked away what he was trying to do. Seriously, how can Lee Pace act without The Eyebrows?
Dialogue - it's great but very fast so I missed chunks of exposition or character moments.
Emotions - if you don't want to cry at a Marvel movie, avoid this. It's tough when right in the beginning you get hit with a huge emotional body slam and that is echoed throughout the entire movie. Groot entirely obliterated me emotionally with his final line. Then there's more sadness! It ends happy but man that roller coaster is very bumpy!
Howard the Duck
In summary, I hope this movie breaks all box office records. Guardians of the Galaxy 2 has been green lit which needs to end pointing them towards Earth so Avengers 3 can be the big team up. Obviously Thanos is trying it collect the Infinity Gems for the Infinity Gauntlet. The tesseract is one, Loki's staff is another gem, the aether from Thor 2 is the third, and in this movie we see the fourth. But is The Collector trying to stop Thanos or is he working for someone else? I hope in Guardians 2 Peter will meet his father.