Game is decent but its no L4D3.
Map design fails it here. The maps are fun but to small and too linear. L4D2's maps were often wide open spaces that gave you different lanes to take on the Zombies. Not to mention there was often lots of verticality in the levels.
Jerusalem level 2 is a good example. Where you have to get the car parts. Its a small space, while in L4D you had similar mission goals but the level area was much larger. Think of the mall where you have to fill up the car. You have 3 (or 4) levels of verticality and a much bigger space.
Seeing 100's of Zombies pour into an area is really neat, but the trick gets a bit old when most of the time you are basically shooting them from really far and all you are really left with is a couple of straglers that might get up close.
For 35$ its decent fun. Hopefully the audience will stay there because already I can tell there is some issues with finding games and I seem to always end up on the Russian missions with quick play.
I would rank KF2 ahead of this game as far as horde shooters, but at the price point its still decent enough. It does some things right like the leveling and the defending aspects, but misses the mark overall.
Biggest pet peeve is the melee. I guess since its 3rd person you can't really have a melee character, but KF2 and L4D its fun to go melee. Here its pretty much R1 auto target.
Overall would of perfered 1st person and the level design needed some work, but again 35$.