Survival Crisis Z is free.
I haven’t had any luck getting it on Vista, but it works fine on XP.
Its an old game, but has garnered a bit of a cult following in its time.
Update: fixed the link!
Update: fixed the link… again! There’s no guarantee it’ll work and at the moment we aren’t going to create any fixes. Our enthusiasm for working on a future SCZ has been somewhat squashed since Project Zomboid was announced.