Killing Floor is a game that will keep you enjoyed for some hours but it's not that good at all.
I like Left 4 Dead a lot and ofcourse i knew this game wasn't going to be as good as L4D i had a good feeling it was stil a pretty nice game.
The first few rounds in the game you probably think the game is pretty good for the money you spend. The graphics are outdated which i think is pretty uncalled for because the creators could also use a new engine in my opinion. But i'm not someone who whines about graphics and i did know the graphics weren't superb before i bought the game.
The gameplay is kind of fun. You'll have to shoot hordes of monsters every round (wave) and if you survive you can buy new guns. and ofcourse every round get's harder.
This seems like a lot of fun but the fact about this game is just that every time you play the game it's always the same. you can level up which is probably the main reason why u would still be playing the game. There are 5 maps in total which i think Tripwire interactive made in a week. Also there's no teamwork or whatsoever, yes you will have to shoot the monsters and heal each other and sometimes weld a door but that's it.
Conclusion: Killing Floor will surely enjoy you for a few hours but when you own games like: Call Of Duty or Left 4 Dead you probably wont be playing this game a long time.