Meh.
Don't get me wrong, I have seen way worse movies in my life.
Just didn't do it for me.
General problems...
-- The cinematography, which was generally bright and colorful in Marvel films after Guardians 1 and since Thor: Ragnorak, felt dark and muddled compared to normal.
-- Introducing time travel as a plot conceit in any film not carefully built around it (e.g., Back to the Future or Interstellar and the like) is incredibly dangerous, and the handwaving they did to just ignore time paradoxes and causality did not work for me.
-- While it was never as bad as Jar Jar Abrams and the wretched mess Star Wars has become since the reboot, there was a 30 minute period there in the middle that veered dangerously close to a clip show... too much fan service/recapping in this one.
-- Did not agree with the end for Captain America at all -- would Cap really just go back and time and sit on his hands? Would he stand pat during the Cold War or while Hydra was taking over SHIELD as he knew it would be doing in his timeline? Would he not do everything he could to help Bucky when he knew he was enslaved by the Soviets?
Yes, he has "earned" retirement and a good, quiet life, but that is the romance and symbolism behind his character. Plenty of good men of his generation had done their part but fought on because there were still missions to complete. This includes everyone of that Greatest Generation from Europe, to the Pacific, to Korea, and the space program.
No way Cap just hangs it up. The fact that he deserves to, more than any other man, but that is would never call it quits is what makes him the hero that he is, no?
Overall, it was alright. It moved product. I was just not that impressed with the plot, the coherence of the cinematography, and some of the choices about characters.