Disappointing, and a letdown, and i'll explain why:

Rating: 3/10 (2 August 2014)

It was okay. It wasn't terrible, but neither was it great. It felt more like a letdown than anything else, not being angry or joyful about it, just disappointed, because I really wanted to like it and tried hard to like it. I'll explain why it was disappointing:
The movie tried very hard to be funny, and at times it was. But me and most of the audience laughed at only 50% of it, the rest felt forced and unnatural. With the funny moments, they were forgettable. I mean with Transformers 4, there was one moment that will always be remembered. The moment when they are in the hall with the old Chinese ladies and Stanly Tucci says "How do you say get the *beep* out of the way in Chinese?" that was worth remembering, the middle finger thing and the blacklight joke was like, meh.
This movie was forgettable, unlike Captain America: The Winter Soldier and The Dark Knight. There was nothing that stood out like those two. With CA:TWS, it had my heart racing with emotion about whether Cap was going to succeed in getting the third Carrier locked, or he would fall and HYDRA would succeed. And the Carrier's being destroyed had been so powerful. The final action scene was very predictable, and you knew Ronan would lose in the end. And the other predictable part was the switching with the Blue guy in the end.
The characters also gave me no reason to cheer for them either. What makes Cap 2 so great was that I was rooting for him to take down HYDRA, but this was difficult to like them.
Peter was interesting and funny at times, but wasn't really likable. Gamora was just there and don't ask questions. Drax was okay, Groot I liked a bit but just felt weird with only "I am Groot." Coming out of his mouth. Raccoon was okay, but not great or impressive.
The action was also not impressive because I have been there and done that many times earlier in the year (Edge of Tomorrow and Captain America: The Winter Soldier.)
Vin Diesel was a complete waste. I'm actually starting to think they just used him as a marketing tool (Slick Disney.), I mean come on he only said like 5 words the entire movie. I wished his voice was used more other than "I am Groot."
Lajohn was right about this probably having no legs in the long run, because when we left, no one really cared about it in the end. I could hear people around us and there mood was just, meh. There was not any clapping at the end either unlike some places.
I wish and I was hoping that it would be groundbreaking like Critics and everybody here on the forums said. But once again, I have been duped by Disney.
This was most definitely overrated by critics and audiences alike, the same way MOS, TDKR, T:TDW, IM3, IM2, were overrated.
And it's not like I'm trying to hate on this movie. I don't hate it, but neither do I love it. When I left, I was just sad. I didn't hate the movie, but neither did I love it. it just felt like a letdown from Marvel, and a disappointment.
The final rating I would give it is about: 5, maybe 6/10.
This movie though does make me appreciate the fact that Avengers: Age of Ultron is coming very soon! Which I can't wait for!
And its ties to MCU weren't spectacular.