I could only try this as a single player : p
Seems to me you have an unfortunate dominant strategy to spam the shoot button? If it's supposed to be that way maybe just autoshoot? idk.I do like though the gun is waving around in a circle, makes it harder. Shooting sound could be more pleasant.
I think the player health textst could be replaced with some sort of graphical reprsentation. A health bar? or bleeding, or something.
I like the loops of movement and shooting, and getting the flag. Simple dynamics that make a complex and complicated challenges.