Do you believe sci-fi and background can't exist together? That it could be a entire crap? The opposite is the reality! In reality, it's 's amusing. Take on the role of a medieval soldier that has the job of protecting the fortress. It's simply throughout his patrol that intruders seem. They aren't comfortable to him and seem odd. But this doesn't have sufficient time to fix, since the enemy is your enemy. Take all aliens that come in the mother ship. You've got your 999 arrows and you will find approximately 1000 of extraterrestrial beings. Perhaps you must hit two simultaneously. Have fun.