I have some suggestions for you 3run .

the enemies start shooting way to soon , there needs to be some sort of a pause for a moment and some sort of reaction before they start shooting at you ,like getting startled /yelling before wasting ammo on you

the enemies different approaches to attack ,is quite good ,however it seems like they never miss ?

the enemies never seem to be caught unaware ,I guess this cannot be any different because they only face towards you always ?

there is never a period of reloading clips ,however you pick up ammo in clips , this kinda takes away the feeling that I am responsible somehow for managing my ammo .

I could probably also shoot through a whole level without worrying about ammo supply , because there seems to be too much of it , how about some enemies drop some pickups , this way you are rewarded for being successful.

hearing enemies close to you on the level within some radius would add to that retro feel ,at this point you are completely unaware of any and all npc's around you unless they're right in front of you .

enemies gang up on you , so the restrictions of the level size really squeezed me into being unable to avoid getting shot.

I know your still busy developing so some of my suggestions seems unrelated , but thats what I thought about..

I like it though , feels solid and there is definitely a doable game within those dynamics .

ps..I get there's unlimited ammo because its a test ,would have liked to have test it on a larger level with normal ammo clip sizes..