Theoretically their brains have already been eaten
Or at least the parts that zombies find edible have been
Though in the Rebuild series it's the venom of a bite that turns people
Most turn. The Rotten in Gangs of Deadville, where this is all specifically given much more in depth lore, are zombies who kept their minds, and can otherwise function. How well varies from person to person. People can also be bitten but not change, and end up immune entirely, which happens to your character in the storyline. Of course, there's also the
- [+] SPOILER
- so called cure that actually makes superzombies, which there is no immunity for
and that's is also part of the main story
Personally I prefer quickplay mode, cuz it's a lot more customizable and a lot less yikes mode
Though you can decide on difficulty