it's easily tied for best TD with Cursed Gems. it is just like cursed gems, but a little better. you get all your money back for selling (which is awesome), you can move towers, the attribute system is better than an upgrade system, nerdy computer references are also awesome, there is nothing to not like about this game.
there are a few things that bug me. one is the badges. im level 20, yet i don't have the easy badge. another thing is that, except for the pistol, all the weapons are short range. The riot shield also slows down a little too much. a sell tower button is a must have, people screw where they put something a couple of times. please add these things to the game. and maybe an actual machine gun, instead of an uzi.