Is this the partitioned area we can talk about Infinity War freely? I just saw it a few days ago.
Overall, I really enjoyed my time watching the movie, although it's definitely not as well put together as the first Avengers, and I agree with Unclebob that Thanos' motivations are a bit too much to swallow (I honestly would rather it be all over some unrequited love/obsession with death).
For starters, Thanos feels oppressive through the entire movie, in a way that feels suffocating each time he's taking action on-screen. This movie more than anything is about him, which I don't know if it's intentional or if it just feels that way because he's such a pivotal part of the story that he seemingly takes up more screen time than any of the other characters. How early on he decimates Loki/Heimdall, brutalizes Hulk, and humbles Thor sets the tone from the beginning. The scene with him and the guardians shows he's not just a brute, but also clever. And the battle sequence on Titan has fantastic moments between the team effort to contain him, Spiderman's "magic punch" and "magic kick", and Iron-Man fighting so desperately for that "one drop of blood" before being completely overpowered.
I also loved Thor's arc, because his moments in the movie were where you could come up for air, get some levity (for the most part), and where the movie generally takes a bit slower pace and gives some breathing room. Him, Groot, and Rocket have some great interactions, and allow both humor and some somber talk to happen that gives Thor more dimension than he usually gets a chance to have.
Dr. Strange/Spider-Man/Iron-Man worked great together as well. The tension between Dr. Strange/Iron Man with the quips and quirkiness of Spider-Man struck a good balance, and 2/3 of the Guardians joining up with them mid-movie was a great layer on top of that.
Where I think things felt a little flat to me were Captain America/Scarlet Witch/Vision/Black Panther segments. Partly because Cap felt heavily stone-faced and lifeless, partly because I have no affinity for Scarlet Witch and Vision's characters or romance that was just introduced, and partly because they've done the "hordes of mindless monster enemies" so often that nothing about this sequence felt particularly special.
The "snap of the finger" wasn't surprising to me only because I got spoiled the end of the movie, BUT, Peter Parker's moment with Tony was a bit gut wrenching for me only because they did such a good job capturing the likely thought process of a kid realizing how badly things have gone wrong, looking to a parent figure for help, realizing it's too late, and apologizing for not doing good enough. I saw my oldest son a bit in that moment watching it, and it was just really tough to witness in that sense. Fantastic dialogue and acting in that moment.
I really do think this movie is going to be thought of by younger people similarly to how some of us might think of The Empire Strikes Back. It isn't a perfect movie, and even if you assume all the "disappeared" characters are going to come back in the next one, I can appreciate Marvel at least leaned heavy into the end of this movie.