@DarkEagle- Zombocalypse: Mostly use the shotgun, it's effective to shoot in-between groups as it will take the entire group. This is especially useful once crowds gather at the fence and you can take multiple out. Also no need to wait on the shotgun to reload fully - you can shoot with any number of shells.
Hurry up and wait games are not my idea of fun. 99.999% of the time they quickly become incredibly boring. Waiting on water to refill so you can play? What's the fun in that? Eh...
Switching between turrets is cumbersome, it's rather pointless to purchase any turret that requires user input because enemies keep approaching while you can't fire. Most turrets are awful. The only good turrets are the machine gun and the passive airships, everything else is not worth purchasing. In the end, this game isn't as fun as it could be.
Game play is horrible and as others have pointed out badges are broken, and the game won't let you past a certain level. Too bad you can't give it a zero star rating.
Boomer is the best character to use to defeat the boss. Once he is on the ground (when he shoots the rockets at you) hit him repeatedly with the candle and you'll finish him off with only having to knock him down once.
I played this game before badges and played it again to get them. Really cool that Geovizz made the upgrades adjustable, so I could go back and get the first two badges without having to reset everything. Enjoyable game.
There's a glitch in the game. If you travel to a city and do not purchase anything, then your health does not reset to 100. Found this out the hard way after dying repeatedly when first starting out.