Great game! I found myself playing it probably a bit longer than I expected. Some of the mechanics were just straight up fun, like when the zombies are low health and when they get hit, they go flying across the map. It's just very enjoyable.
One game design thing you might want to consider - you had it so that you could "stock pile" arrows, up to 5, allowing you to shoot them rapid fire. The question is what value does that bring the player? Right now there's no benefit to the tradeoff, you could either wait for the 5 to pile up, then you shoot all 5. But that seems like it takes longer than just firing off 1 at a time (basically button mashing).
Great job overall.