Seeing people who decide to make a 3D game for a jams makes me happy.
The low poly art style is charming and is really easy to know what's infected and what's not, the upgrades are fun too, seeing the different infected become faster and the x-ray vfx with the entities so you can see them behind objects is so smart.
Something funny is that sometimes other infected get trapped in trash dumpsters or in narrow places but when this happens you have so many others that it doesn't really matter.
This can be a good starting point for a bigger project.