Cool, a zombie shootout! It would be awesome if there was multiplayer support someday — or even local split screen for two players. It reminds me some oldschool co-op arcade games. Not sure about the style fits the theme yet, but Im curious to see where you take it, keep going!
Btw, any chance to lose the game besides running out of health? I mean I didnt get what exactly serum does. Also, just a small tech question - is there a reason the build size is around ~1Gb?