Great work. I loved the sound effects, art, player design, and overall game feel. It felt good to run and shoot at the same time. However on my end the game runs very choppy, and certain art pieces would load in and out. I also wasn't sure whether I was hitting the zombies half the time, so maybe an indicator (whether UI or particle effect) would be useful feedback. I wasn't sure where to go or how long I had to hold out so maybe mention that on the page or before the game starts.
Overall this was a solid project, hard to believe you made it in just a week! I am excited to see what you can pull off in the future, or on a sequel of some kind.
-Leo.