The final scene was a bit weak, I had no problem with them disappearing right in the last scene but I feel like it would've worked better if they hadn't just shown the ufo right before it. Have them examining the burnt landscape, cut to everyone in town leaving the basketball game and then eventually cut back to the empty field. Everything else in the movie had done a good job setting up that the 'something in the sky' was a real thing and not just a couple of nutjobs listening to static on a radio, so the actual spaceship reveal felt unnecessasry as it didn't really confirm anything the entire rest of the movie hadn't already done in its own way.
Outside of that and the fact that it was a bit short, not only in runtime but in a 'that went by fast' kind of situation, it has everything else I want in scifi.