Okay I was able to place towers and the robots would go to it. I shot down some of the alien things which was a bit tough with no crosshair and the super high sensitivity and low FOV. The gunshot audio was loud and so was the reload so that surprised me. I continued along placing and picking up the towers as I went and then suddenly my robots had been destroyed! I guess there was an alien that spawned behind them or something. The end of game screen has a go back to menu button but there is no menu.