Finally saw it today and it was alright. It reminded me a lot of Thor 2, except this was made with more heart and soul. The villain was completely interchangeable though (like literally, him and Thor 2's villain could switch places and nothing would be different) and I retain my opinion from the trailers/clips that they made the Marvel Cosmos' population look terribly bland. Outside of the main characters, all the aliens were just people with make-up. Some in red make-up, some in blue make-up, some a bit more detailed because they have a few lines, but in the end, very limited. It might be a nitpick but it doesn't help the aesthetics weren't too diverse either. None of the settings stand out except for Knowhere's exterior , but once inside it's all grey drab again.
Also, I have no idea how Zoe Saldana was cast. Actually, I do, and acting skills certainly weren't a part of it. She botched so many of her scenes I genuinely think Megan Fox could've outdone her, and it didn't help that the chick that played Nebula outclassed her easily in all their scenes together. Then again, the Gamora and Drax portrayals were my least favorite parts of the movie. They are supposed to be the team's bad-asses, but both got weakened and dumbed down to near offensive levels.
In the end I didn't like that so much of it seemed to roll straight out of the Marvel Movie Generator, but luckily the movie still had enough going for it to make it a decent watch.