Basic hold off the zombies map, you get some time to prepare, then to door opens and the mayhem begins. Its pretty challenging the first time...but after a play or two you'll get good at it.
Critisim Welcome.
Oh yeah, the tv doesnt work right, but its there....
No way I can hold of headcrabs that bring me to 1 hp will I have no real walk area to get away from all the other nasty headcrabs.
When I did found out the secret it was pretty easy.
Just put the turret, in front a large box and it's just a matter of waiting.
When the turret got the destroyed and all the lil' headcrab came to me I just used my gravity gun and they couldn't kill me.
In other words, without secret, to hard, with secret, to easy.