Dark and intense story. Loved it!

Rating: 9/10 (10 May 2018)

I have been waiting for this very long time and I loved it. I wouldn't say it was the best movie but I found the plot well-thought in general. Here are some ups and downs:
Ups

Pace of the movie. During the entire 2 hours 40 minutes I was never bored. It was dark and intense. You immediately feel that the stakes are very high.
Thanos' philosophy. I like to see the background of the villain. I liked how Thanos' ideas were depicted. At some point I even felt like his ideas make sense to some extent. (I don't justify his actions)
Thanos not being defeated. I don't like when they just defeat the villains at the end of every movie. It was more interesting to see Thanos alive and enjoying sunrise (or sunset) at the end. It was also interesting to see all these people disappear at the end. A lot of questions...
Thanos' vision towards the end. It was interesting to see the little Gamora scene. I don't know what it means but I like it.
Gamora's death. I love when they kill some of the leading characters. It was also interesting to see star-lord's reaction when he tried to fullfill Gamora's last wish. That was a bold move.
How other stories were connected. I have seen almost all Marvel movies. It was good to have a better background with all these characters instead of meeting them first time in the movie. DC should have done this too.
Captain's return. I liked the scene where Captain first showed up. He is darker and very decided. I loved how he didn't give a damn to that secretary of state.
Thor's new style. Looks better with the eye-patch though. I liked his new hammer and fighting style. I would prefer the eye-patch since it makes him badass.
I loved Fury's line at the end. Motherf...!

Downs

Connection from Gamora's capture to Soul stone. It was clear that Thanos didn't know the location of the stone. It felt a little weird that it happens to be Gamora was with Thanos and ready to be part of the sacrifice. Did Thanos know beforehand that he needs to trade for her life? If the answer is no, then it was a cheesy plot.
Gamora willing to sacrifice herself but not her sister. She looked like a tough gal who clearly thinks that half of the galaxy dying is more serious than one person's life. Yet she gave up too easy. She doesn't even like her sister that much.
Aliens have incredible technology to travel from galaxies but they fight on foot. This happens in almost every superhero movie. Can't they do something better? In terms of both having a well-thought plan and advanced war weapons. They literally attacked with some alien animals.
War in Wakanda. Aliens are on earth, and we fight them with several hundred on foot soldiers. Where are the military forces of other countries? Why don't they just send missiles or air forces? Why is this so local? If the writers wanted this to be a local fight, they could have shown some UN people refusing to be part of the war at Wakanda, or something like that.
Thanos waits years then decides and manages to collect all the stones by himself. That was a little too fast and easy.
All villains look crapy. Proxima midnight was disgusting. Why is that? They can look better and be cruel. Actually that might be more interesting to see. For example, Hela from Thor: Ragnarok.
Villains without background. I liked how powerful Ebony Maw was. They could have also given him more motivation or a little background. We don't know anything about all these black order people.
Loki's death. I didn't really get why Loki got himself killed like that. He was famous for being mischievous. He also kind of served for Thanos before, why didn't he this time? I mean I am glad he is dead, that made the story darker from the beginning but Loki's sacrifice didn't feel natural.
Give this a man a shield scene could be better. I felt it a little fast. This moment could be just couple of seconds longer and more dramatic with epic music on the background.