Another "Shoot'em before they steal your whatever"
As the previous poster said, the title is ill fitting, also, if you HAD made a farming sim (Harvest Moon comes to mind) I think it would've been more entertaining, not to mention original. People get tired of "SHOOT IT" mighty fast unless they're deranged.
As for the game itself, I found it to be quite awkward. I say this as when the UFOs drop... Whatever it is they drop, (crop markers?) sometimes they'd land right on me and nothing would happen, others, I would shoot them from a distance and die. I saw no life guage, so I assume it's "One hit and you die". If that's so, fix it so that holds true.