Is it fasting when playing shooters like Fortnite or BO4?
In Islam there's a ban on images (regardless of fasting)
No it does not. Breaking fast would be things like eating, drinking, smoking, having sex, etc.
No, but such things should be avoided in Ramadan. Eye, ear and soul should also fast.
By the way, you can generally see if you can play the games at all. I do not know them, but if they include sins and haram, you can't play them, except that they are also addictive and a waste of time. Especially in Ramadan, where you should use the time meaningfully and make increased worship.