Simply awesome
This is way the best defense game i've ever played, but it could have been even better if you had put a boss every now and then, like zombies bigger than the base... plus, there could have been more expensive weapons, like a rocket launcher for 15,000 exp or something and more powerups, like even more increased walking speed or faster reload... I really hope you'll make a sequel, with more weapons, more zombies and more violence, YAY!