No collisions was crap, you trapped a human in a room and he could just run tru you and escape. + it made hitting humans such a bitch as a zombie. But yeah i remember a few things You had crap luck if you got the Mac 10, M3 super or Health instead of regenerationFast headcrabs made such sexy gib sounds *splat*Sniper rifles (why are they gone D:?)Fucking rambo achievement (oh god i remember punching my keyboard when i had 86 kills on ventilation, and we had 5 min left. I was gonna get it. LOL CRASH)