Lots of fun, but lacking in some necessities
Great job, overall. I enjoy this type of game. Most people that are reviewing your game mention grammar, sound & the inability to save or at least restart the level instead of starting over @ lvl 1. I have to agree with these critiques. These problems can make a game frustrating, instead of enjoyable. Other than these problems, it truly was lots of fun.
For those of you complaining that the game is too hard- here's the 100% victory formula:
If you can afford it, priority #1 is lay down your turrets all the way to the right. Cluster them together. When you use up all your power, wait till you can afford a powerplant then smack that down away from enemy fire. Rinse, repeat :D Factories come later, but they are important, too. You'll know when the time is right for them^^ Salud