You lose when there are too many mobs on the circle (100 x player). You win if you survive all waves (40).
1.9e the same but debug mode disabled. 1.9d Fixed display price of Upgrade to antiair lv2. Fixed Lv16 getting stuck sometimes. Added 130% diff option. Fixed/added some tooltips. Added a warning when the circle its 85%+ full. Other minor changes.