Overall, it functions really well as a tower defense game. The choices of towers that you have to pick from all feel well balanced and distinct, and the economy the game runs on to build and upgrade these towers is solid as well. Only real feedback i can give is maybe lower enemy health a bit, as towards the start of the wave, nothing really does enough damage to take out the ants in time before they breach through. Additionally, having to click a button to close the menu is a bit tedious for me personally, I think it would be better over all if you made it so simply clicking outside the menu popup would make it go away. Overall though, really solid build you have here :)