The problem
I wish Factorio (handheld) weapons would become gradually less effective when faced with tougher enemies. Unfortunately the current Factorio weapon mechanics makes weapons completely useless when faced with bigger biters.For example handgun - it will never protect you agains a group of medium biters. Wouldn't it be more fair if instead a clever player could still use a handgun in combat with some maneuvering? That's what I would call a "gradual degradation of usefulness" - the bigger the enemy, the more skill one needs to avoid it (or a pricier weapon). Handgun is just an example of course, same works for the assault rifle, etc.
Suggestion
Damaged enemies should run slower depending on the level of their damage.How will it improve the game?
If bullet damage slowers Biters down, low-powered weaponry (think handgun) become much more useful.Imagine running from a horde of mid-sized biters while having only a handgun. Currently there is no point in shooting because even damaged biters will catch and kill you. But with this suggestion you can shoot a biter and keep running, and the biter will slow down and drop from the pursuit. That way with some skill and a minimum of ammunition one can save themselves from any horde.