This is a great idea, and is really fun to play. The animations are fantastic and very satisfying

Good game! Well polished! 

Here is my feedback:

What do I like the most?

• The mechanics of the game.
• The animations. 
• The music.

What didn't I like?

• The zombies, they look crappy, especially their animation. xD
• Shooting SFX.

Bugs/ To fix:

• When I moved the player with arrow keys, the page went up and down. 
• The zombies glitches if they collide with each other.
• Sometimes, the zombies glitch with the player.
• When I pressed the 'Q' key, a window shows up, where I can edit in it the timer, ammo, etc. [1] (I think this was for debugging)

Suggestions:

• You may have an idle animation for the light if the player isn't moving.
• Maybe, enable switching the game to full screen.

Endnotes:

[1]