To be honest, the game here is great and this is one of the best incremental game I've played. Problem facing here need to be the out of range numbers going to negative. After several rounds of playing, reaching maximum money and build start to go consistent. Then two thing happens.
1. At round 800 something, it registered 52 foes left but undetected. Not able to skip wave and the timer stops. Game stuck and I pressed give up button.
2. Start bonus now becomes a +-796138089, which is basically a zero in game.
Hope your game will improve over and over!