What does the Avengers movie have to do with writing, you ask. I'll tell you. Like all good novels (and movies) you want to tell a story in three acts. This movie follows that outline closely without straying outside the lines too much. In your first act, you must have a life changing event that throws your character(s) into chaos or else you'll have a very short story. In the second act, your protagonist better be up to speed and the trouble better escalate. In the third act, things should have come to a boil with seemingly no hope in sight until your protagonist comes to the rescue and saves the day.
Okay, The Avengers did that. (Spoiler Alert) The evil bastard, Loki gets orders to destroy the Earth from some ugly dude with a bad case of gingivitis. Things go bad when he steals some secret Rubik’s cube that has more power than a Solyndra solar farm. S.H.I.E.L.D. gathers my old heroes from the sixties, when comic books were my life, and now, with the formidable team of Ironman, Captain America, The Hulk , Thor and some other guys, (and a hot Scarlett Johansson), go after 155 pound Loki who looks like a Mardi Gras transvestite. (Can you tell I didn't like the movie, yet?)
Then the trouble escalates with Loki opening the ozone hole (I think from the methane gas this stinker produced) and a zillion bad guys, who make the Imperial Fighters from Star Wars look like sharpshooters, come down to Earth single file so the good guys can pause to talk between battles.
Finally (interminably) the heroes kick the bad guys butts and set the finale up for a sequel.
Okay, then. So why does this movie suck so much I wanted the bad guys to win? The answer is in Novel Writing Rules 101. You must have an interesting protagonist who readers (viewers) care about. The Avengers had too many protagonists and none of them were likable. I didn't care about anyone except for that weenie S.H.I.E.L.D. agent who gets killed just like Jack Nicholson in Mars Attacks (best movie ever) except it wasn't funny. The guy who plays the Hulk rubs his hands together like a schizophrenic and emotes a lot. (Hate him). Robert Downey Jr. did not make Robert Downey Sr. happy with his "I don't want to be here but they offered me more money than Kobe Bryant." attitude. (Hate him.) Thor was cute and had an Australian accent so my wife loves him, but I hated him. Captain America was just goofy and has zip for powers. He's kind of like Batman in the Justice League, always trying to keep up with the guys who actually have super powers. (Really hate him) Then there was Scarlett Johansson. (Love her) She could have stood against the wall for the whole movie and still been the best thing about the Avengers.
I know, I'm a majority of one. The movie made a billion dollars and all the critics loved it. I don't care. The director focused on CG with a lot of noise and never developed the characters.
It was an awful movie and would have been an awful novel. I felt cheated by the movie and the theater, but I got my vengeance by not throwing away my empty popcorn box and coke cup when I left.