This game is well.... ok. Its an amazing game for the price, but isn't a ground breaking game either. I'll try and list some pros and cons of my experience.
Pros:
The graphics are very nice for a low price
Killing zombies on a budget. This game is great to just hop into complete a level and kill some zombies.
Lots of different weapons to unlock which creates replayability.
Good voice acting
Good story through tablets scattered around the map.
Lots of little areas that you can go in for extra money and zombie killing

Cons:
You can't jump
When you don't sprint movement is unbearably slow.
Gets repetitive very quickly. Killing zombies is fun for a time

TLDR
This game is good for the price, its fun to jump in and kill some zombies but gets old easily.