Take the advice
You really have to take the advice and go on the Low Quality setting. When I tried on "High" I could barely even tell what I was supposed to be looking at! This was still a fun game because it had a lot of interesting character designs. Some color effects seem off, but what I liked was how everything just seemed so original! The designs of the monsters are good even if the graphics are not the best. My biggest suggestion is that you give a wider range to fight.
Speaking of the range, it is cool how you can shoot some enemies before they come into your range. The sound effects are quite effective. For something about zombies, this actually wasn't as good as I thought it would be. I guess I am just so used to killing zombies it doesn't come off as frightening. Good overall.