C-, mainly for some nice alien FX....otherwise, it was pretty stupid. What sort of strategic advantage would aliens advanced enough to make it to Earth after a recent message into space have by fighting in the water instead of the air or space? Why are they firing missles with scarely more power than Earth missles? Why did the lead protagonist of the movie spend 10 minutes looking for a chicken burrito?
Meh. I didn't see the film so I cannot comment on whether it's good or bad or not but generally I think this is an unfair criticism.
Star Trek fans typically are very forgiving of Trek for it's outright often absurd magical engineering solutions to problems that are only instantly forgotten 3 episodes later where the same problem could have been solved with the one they just used.
I'm willing to suspend my disbelief for Trek and for other sci-fi films that fail at the poorly thought out engineering generally to resolve plot problems.