I loved the visuals in this, and Amy does a great job of carrying the cast. I am able to suspend my disbelief for 120 minutes when watching sci fi, so I will avoid the useless "but that's not what the military would do" comments.
The movie has a great setup talking about language, culture, our perception of the world and how truly -alien- an alien life form would feel to us.
Unfortunately, it uses that setup to deliver a platitude older than written language and then just throws away any conclusion to its sci fi story that we though was the main focus up until that point.
Yes, I know cancer is sad and all that from real life, now can we please know what happened to the aliens?? Did they get bored and leave when they saw the ending?