not stupid There have only been a few 'realistic' sci-fi / first contact films and this is one of them. The central conceit is that the aliens are testing our abilities, to see if we're worthy and intelligent enough to meet them. Given that they, again, decided to drop into the USA, they were increasing the risks but.. there's always a maths genius somewhere to rely on.
Amazingly, the story does seem consistent.. I couldn't see any obvious plot holes. The only silly thing is that it's a bunch of YAs rather than proper scientists that play the central roles but that is, sadly, more about cinema economics than reality.
Overall.. a decent effort