I played it till completion, I have some gripes. The game overall plays fine, nice variety of weapon and enemies, level in the house is nice, random cars driving around killing monsters are cool, level in the high school is also fun, no problems with pathfinding. I agree with problems counetd by GorriDev though, monsters are far apart, suburb levels are too big for their own sake, the destruction is pretty low at the start (only your house is damaged, other houses don't have any damage and we even have lanterns working). First level needs to blow your players in the face with explosions, earthquakes and scripts that pump their adrenaline. I learnt that you can roll and sprint by chance. Tonal shift is also a little jarring, monsters killed your parents and there's blood everywhere but monsters are funny little creatures and bleed green goo. Most confrontations play mostly the same, tun away while shooting at enemies. Camera is too close to the edge when going up and down.
If I can recommend something, have your first level a little more linear with bigger destruction and fire everywhere, current level should be for later when you have more weapons and filled with more enemies. You have a good start, now there has to be a way to make it more exciting.