alarm

alarming

warning

alien

danger

emergency

escape

evacuation

panic

red alert

alert

noisy

aliens

science fiction

buzzing

caution

nuclear

game

sci-fi

breach

scifi

fire

loud

military

spacecraft

control room

intruder

spaceship

war

security

system

siren

urgency

sound

extraterrestrial

noise

bleeping

beeping

bleeps

beeps

attack

buzzer

attention

buzz

sci fi

bleep

beep