Pretty cool
I only have two slight things to moan about on this game. First, every other enemy appears to actually travel over the tanks, as in figures that should be behind them on the view are in front. Second, slight bug where i simply stopped being able to fire at about day 25(Not that i didn't have enough to handle it without me:). Other than that, good defense game and well thought out.
And to the reviewer before me, the problem is at your end because i didn't get any lag throughout the entire game.