Do you know this game? i think you should.
this is legendary Left 4 Dead 2 (in case if you don't know).
OK,this is game where you get out of shelter,kill zombies and then get in new shelter.
nothing more to say here are some screenshots.
system requirements
CPU:more than 2GHz
GPU:Video Card Shader model 3.0. NVidia 7600, ATI X1600 or better
RAM:2GB
HDD:16GB