I like the vision for your project! Implementing multiplayer in a game jam is very ambitious. I can't imagine designing multiplayer AND making a game too. The servers are kind of dead though XD
I keep running out of ammo for the gun I have and the enemies can still hit you when you use the melee. I had to learn to conserve my ammo and that helped a little bit but eventually you get swarmed. I also keep forgetting to manually reload!