Gah!
Some people don't understand defense games.
First off. I liked it, but I don't think your forces had enough variety. Only 5 ways to fight of the many different enemies you were given, and not enough money to do what you needed. Plus, it would have been fun if you could buy helpful programs. Such as a program that increases your computer's running speed, thus making units fire faster. Or maybe one that would slow down viruses, or perhaps buying units that could slowly repair other units?
I don't know, it just seemed like there could have been more, and I was happy, but it's not my favorite game.
I don't have a problem with the graphics, though, everything seemed well designed, and I was generally pleased. But I just wish it could have had more.