Guess you could call it a bug, more like a slow loading problem though.
From beating the very first level (Starts out with alot of cash), but when you advance to the second level, the whole map went white, than slowly started filling in textures/units O.o and than once it was actually done loading the map it pulled up the ‘Please Wait Loading’ XD.
Besides that it looks great, might want to fix when you’re (kind of like on your desktop, where you can hold down the mouse and drag out a 3DRect) dragging that Rectangle out if you’re mouse is over a Resource like a Mining place, it will render the black money sign over the gray 3DRect.
What else…
When a Lazer Tower (On the second level, as far as i got) is shooting, the animations chop off and on, maybe missing frames?