This is a game when my daughter came home from college this past year and brought her friends they wanted to play. Totally recommend you pick it up(the older ones) or pick this one up, and sell the exclusives on Ebay for a profit. Or some combo of the 2. Fun game for friends and family that isnt electronic.
https://www.kickstarter.com/projects/coolminiornot/zombicide-season-3
You can play this online with Tabletop Simulator, it's pretty damn fun and a game can go on for hours if you really care. I typically try to make the game end sooner, rather than later, though, because I don't like to get swarmed by a horde.
yeah if you dont clear out the zombies you will get overwhelmed.