Gets boring quick. Though a good game while it lasted. If I were to make improvements I would create an 'auto spawn' button because it gets really tedious where you're just clicking the spawn button as fast as you can when it gets to lated stages. Put more upgrades and put a 2x, 3x, 5x as well as a 10x button, that 10x is just too fast in some situations.
Ya its an awesome game. The first time i used a transport helicopter, I didn't kno how to tell it to land so i was like yelling at it to stop and drop off the guys lol