Armored Warriors - Metal Defense Invulnerable Ver. There are Easy and Hard mode to choose. Under easy mode monsters will only appear from the left or right side of the screen. Score will be low under this mode. Under hard mode monsters will appear from anywhere. Score will be high under this mode. Do what you want in the invulnerable version! A: Gun attack. S: Blade attack. D: Mine attack. Arrow Keys: Move left or right. Space: Run