Needs rebalancing
There weren't enough enemies per wave to upgrade as often as would be nice. Also, you should get full energy at the beginning of a new wave.
On the plus side, this game was great. The enemies were well designed and the idea was good.
The game also needs to be longer with more upgrades and maybe a few boss enemies.
Really cool.
Everyone loves tesla coils, and this game proves it.
My only suggestion would be to put in a flashy targeting reticule instead of the normal mouse cursor.
Other than that, really good game with awesome enemy models and lightning animation.
Lots of Potential
Now, in terms of Tower Defense games, it's kind of hard to be original since the idea has been done thousands of times, but this game has some potential. The visual design is awesome, the gameplay is simple but fun, and the sound effects are top notch. However, as you've heard many times, the upgrade system is far too simple and even the game as a whole is too short. If you decide to make a sequel, and you improve these aspects, you've got yourself an A+ game here =)
Da'n good zapper!
That's like in good, old C&C!
Great Idea
i love it :) 5/5