The same concept to Dojo of Death: spawn caps are set, you can pretty much walk around and herd your zeds, sometimes waves of them will join the game though. Make sure you have 1-3 to shoot at all times, otherwise it gets boring.
If you liked the Bridge Builder under DOS...
Don't play this game. Seriously, don't. This is an abomination of the bridge building genre; the controls are below the minimum expected, even for flash games; the levels have nothing to do with engineering or other slightly challenging riddles. It's a firm 1/5.