Ok, let's start with the best- you made a 90's looking game that emulates 80's looking movie, and it works really well. I would prefer for it to have a bit more light because all the buildings look to dark and you really can't see all the detail (I remember your "work in progress" posts on discord). Audio was good- fit the gameplay and atmosphere, but it wasn't as polished as the graphics.
As for the gameplay I have what they call a cognitive dissonance. I loved the driving model- it felt floaty, but in a fun, not frustrating way :) The walking gameplay... I think you could cut for a jam game. Just driving around was fun enough, and the walking felt more janky. If the survivors came to your car when you stopped near them (gta-style) it would be faster, than stop the car, talk to survivor, return to car. As for the core gameplay loop, here I have some problems. The game starts with "survivors in the stadium" and my first thought is "but I don't know where the stadium is!". This sorta repeated throughout all the game. If there was a minimap, a crazy-taxi-like arrow, or (coming back to my previous point) more light, so I could recognize the landmarks from a larger distance. This would largely benefit the gameplay. Also- I can save the survivors at the police station, but I have to escape by helicopter? I was so confused by that :)
The use of theme was on point though!
Over all- this is a seriously ambitious project, and I think it trips over it's ambition a bit. Each of the elements is great, but they don't fit together as well as they could.
One more thing- WEB BUILD! This would easily be one of the most played games in the jam if you had it!