I enjoyed it. Obviously not the best of the MCU but to me not deserving of the low rating either.
Questions I had were how they almost involuntarily went into the unimind. One wrap up video explained it as the connection to the baby celestial forced the unimind to begin. Not sure.
Have a feeling that we see Ikaris again. And can't Arisham just reprogram another version of him and for that matter can't he just regenerate the other "dead" eternals West World style. It was never explained how biological they are. I prefer the comic versions of eternals where they are just modified humans.
Also, one scene that bothered me was the Hiroshima scene. First, how'd they actually get there? There is still a war going on. It's not like they could just hope an airliner or take a cruise. ANd it wasn't established that they were part of a military unit, of which there'd be no Allie units there on Aug 6 1945. Second, where were the survivors? The bomb used at Hiroshima wasn't like a modern nuke. It wasn't nearly as powerful and there were survivors milling around soon after the blast. There are pictures of it.

2 western looking people standing in plain day in a Japanese city during WWII would NOT have gone over well. Soldiers would have spotted them miles away and come to kill or capture them. Third, to be there, they'd have to know it was happening. They wouldn't have. Finally, Phastos cries b/c this was such a horrific event. I was left thinking that of all the equally horrible things that went on since the mid 30's through that day, THIS was the one that sets him off. Never mind all the genocide, combat deaths before Hiroshima and the entire war that went on. Also, never mind the fact that the A bomb prevented a much more horrific invasion. The A-Bomb gets too much credit for being "horrible" b/c of the optics of being the first 2 A bombs used and the implications. I get that. But as a history buff, scenes like that are so overly simplified and lose context to the overall horror that WWII was. I'd have preferred a more intelligent scene of Phastos lamenting the entire war and the technology he helped kick start but set after the war maybe was part of a crew in Japan there to help occupy and assist the citizens of post war Japan. Didn't ruin anything for me just don't like these over simplified scenes that would have never existed even in a comic book universe.