There's also a thing where you can only push the zombies so many times before it makes you wait a certain period of time to push again. Too bad the demo is only the first half of the Parish on Steam.
Charger's are pretty strong, but they aren't as bad as Jockeys. Jockeys are the #1 annoyance on The Parish (only one I've played).
Totally epic though. Not rushed at all.
And by the way... ELLIS FOR THE WIN!!!!!!!!!!