It's not as if they ruined it completely, it started off well. And the whole impression was not soooooo bad, the thing is you can't help feeling like being rushed into it. It's like being constantly slapped in the face. The story spans a couple of years and it would have been refreshing, not to mention more enjoyable, if the director of this one found a way to spontaneously connect the plot rather than just put "two years later", "8 months later" on the screen.
Also, my second Matt Damon movie in a week makes me reconsider my (dis)like for the guy. He's being sentimental here, afterall, it's a romantic drama (which is too bad 'cause I was hoping for SF) and he's good in it. Can't complain. Emily Blunt is fine, as well, although at times I experienced that cringy feeling that I absolutely abhor (I guess her rudeness and swearing and showing her finger at the future senate candidate Damon was somebody's brilliant vision of re-writing Dick's 1954. short story). Anyhow, I adore John Slattery and was, again, somewhat bummed at not seeing him on-screen more while at the same time being pleased with Terence Stamp's performance as a loveable maniac - typecasting again.
The biggest problem I have is with the ending: rushed, stupid, predictable, stale. Happy, of course - which is too bad. SF moments are minimal and almost not present, the genre turns to romance too quickly and that is.......you guessed it.........lame.
So, with the utmost regret, I have to give it 6 out of 10.