On one hand I was never bored and I wanted to see what would happen next at all times. On the other hand I never felt any particular emotion. This is a large scale story about planet-wide civilizations, and the movie carry us on a ride of this scale, with very impressive visuals and big fucking things (ships, battles, creatures, anything). All of this is pleasing to watch, and made with an elegance that gives it an impression of grandeur. This is where the movie gets my A-rating. You can corrupt me with any about a story big enough to make it look like it's playing on the "Significant" league, and well-crafted enough so that I don't spot the fraud.
There is a bit of awkwardness in the way the story blends human-scale events together with civilization-scale events; at some point I asked myself "Why am I watching this particular scene involving those persons, which seems like an anecdote in comparison to all those big-scale things happening in the story". I think this problem of integration between the important and the detail is at the heart of the movie's weakness, which is its inability to convey strong emotions.
A note on the music: the movie is fucking LOUD, and extensively uses modulation of the volume of Hans Zimmer's soundtrack in order to make everything ultra-giga-epic. This is a trick that has been used for the last two Nolan's movies (Dunkirk and Tenet). Nolan defends the "sonic" quality of his soundscapes and says it's entirely intentional for it to be so loud. I guess Denis Villeneuve thinks the same. I think it's easy.
Anyway, the 155 minutes passed by like a flash, and since the ending is actually an opening, I'm all set for Part II.