Not too bad....
It might have even been fun if it was not a resource hog. I couldn't get past wave 10 before the lag made avoiding enemy fire impossible. It was not a new idea, but it was pretty, and that was its downfall. older computers like mine just can't run games like these. you should think about that before you make games that require so many resources to run. The camera movement was also rather disorienting, though it was the least of my criticism.
add that to the "it's not new" and the "you can't buy extra lives" and the "you can't remove or replace turrets" and this game is pretty subpar.