I really liked the apartment the player started in, very nice work there, although it lagged a bit for no obvious reason.
The entity placement overall was really good, so well done on that.
The first zombie scared the hell out of me! Other than that though, I wasn't keen on the enemies, because a) their placement wasn't as good as it could have been, and b) they simply didn't attack. I had to get really close to some of them before they seemed to notice me, and then if I backed away, they stopped following me. Also, players don't like being attacked from behind.
The city was pretty well fleshed out, with all those building entites, but I did notice they weren't standing on anything when I jumped over the fence. Either move them closer, or move them lower down.
I got between 8-30FPS, but averaged between 18-26 FPS, which is alright considering the size of the level and number of enemies but it would have been nice to have it a little higher.
Overall, this was an alright first attempt. There's still some things that need ironing out, and there should be more atmosphere. It says when you get near the telephone that you're trembling. I don't know why, but I just wasn't. Maybe zombies just don't scare me...
AE
EDIT: Btw, my specs were:
Pentium III 2.8 Ghz (just the one)
1 Gb RAM
XP SP2