Loved this game back on the PS3.. via PSN store.. was glad to find it awhile back on Steam.

If you enjoyed the original GTA (aerial view) and possibly ever played Desert Strike or Jungle Strike on SEGA Genesis then you will really like this game. Same concept, little story with missions where you rescue folks from buildings and other places while zombies attack.. then bring em back safely.

Also has a Racing mode which is a blast, reminds me of a Mario Kart like scenario.. Race + Kill to Win!

Fun older arcade like game.. mindless driving, squashing zombies, and also has a Slaughter mode where you can just fight off Waves of Z's for as long as possible.