wickedly sweet game, but a few problems
It's an awesome game, no doubts about that, but I did have a few problems with it. For one thing, it takes a little too much time to get enough EXP to get a better weapon or powerup. You could solve this problem easily by increasing the amount of EXP for the blue, basic starter zombies from 5 to 8-10, and keep going up the chain like that.
Also, with the Mossberg 5000 (1st shotgun), it takes too long to reload it, unless of course, he's reloading it 1 shell at a time, which still makes the Mossberg 5000 a worthless investment, since 8 shots at the price of a 6 second reload means that by the time you've reloaded, the zombies are already swarming over your base and beating the crap out of it.
And, finally, you should make it so that the player can switch weapons the moment the magazine hits empty, instead of being forced to wait a few precious seconds whilst the little dude in the game fumbles around (and yes, I do mean fumbles around. I can reload a pistol in way less than three seconds, and I'm talking about my old Colt M1911) trying to find a clip and figure out which end goes in first.
But, other than those few problemos, i think it's an awesome game and should be a required play for people who are thinking about making a Zombie-killing game.